github.com/CanonicalLtd/go-sqlite3@v1.6.0/sqlite3-binding.h (about) 1 #ifndef USE_LIBSQLITE3 2 /* 3 ** 2001-09-15 4 ** 5 ** The author disclaims copyright to this source code. In place of 6 ** a legal notice, here is a blessing: 7 ** 8 ** May you do good and not evil. 9 ** May you find forgiveness for yourself and forgive others. 10 ** May you share freely, never taking more than you give. 11 ** 12 ************************************************************************* 13 ** This header file defines the interface that the SQLite library 14 ** presents to client programs. If a C-function, structure, datatype, 15 ** or constant definition does not appear in this file, then it is 16 ** not a published API of SQLite, is subject to change without 17 ** notice, and should not be referenced by programs that use SQLite. 18 ** 19 ** Some of the definitions that are in this file are marked as 20 ** "experimental". Experimental interfaces are normally new 21 ** features recently added to SQLite. We do not anticipate changes 22 ** to experimental interfaces but reserve the right to make minor changes 23 ** if experience from use "in the wild" suggest such changes are prudent. 24 ** 25 ** The official C-language API documentation for SQLite is derived 26 ** from comments in this file. This file is the authoritative source 27 ** on how SQLite interfaces are supposed to operate. 28 ** 29 ** The name of this file under configuration management is "sqlite.h.in". 30 ** The makefile makes some minor changes to this file (such as inserting 31 ** the version number) and changes its name to "sqlite3.h" as 32 ** part of the build process. 33 */ 34 #ifndef SQLITE3_H 35 #define SQLITE3_H 36 #include <stdarg.h> /* Needed for the definition of va_list */ 37 38 /* 39 ** Make sure we can call this stuff from C++. 40 */ 41 #ifdef __cplusplus 42 extern "C" { 43 #endif 44 45 46 /* 47 ** Provide the ability to override linkage features of the interface. 48 */ 49 #ifndef SQLITE_EXTERN 50 # define SQLITE_EXTERN extern 51 #endif 52 #ifndef SQLITE_API 53 # define SQLITE_API 54 #endif 55 #ifndef SQLITE_CDECL 56 # define SQLITE_CDECL 57 #endif 58 #ifndef SQLITE_APICALL 59 # define SQLITE_APICALL 60 #endif 61 #ifndef SQLITE_STDCALL 62 # define SQLITE_STDCALL SQLITE_APICALL 63 #endif 64 #ifndef SQLITE_CALLBACK 65 # define SQLITE_CALLBACK 66 #endif 67 #ifndef SQLITE_SYSAPI 68 # define SQLITE_SYSAPI 69 #endif 70 71 /* 72 ** These no-op macros are used in front of interfaces to mark those 73 ** interfaces as either deprecated or experimental. New applications 74 ** should not use deprecated interfaces - they are supported for backwards 75 ** compatibility only. Application writers should be aware that 76 ** experimental interfaces are subject to change in point releases. 77 ** 78 ** These macros used to resolve to various kinds of compiler magic that 79 ** would generate warning messages when they were used. But that 80 ** compiler magic ended up generating such a flurry of bug reports 81 ** that we have taken it all out and gone back to using simple 82 ** noop macros. 83 */ 84 #define SQLITE_DEPRECATED 85 #define SQLITE_EXPERIMENTAL 86 87 /* 88 ** Ensure these symbols were not defined by some previous header file. 89 */ 90 #ifdef SQLITE_VERSION 91 # undef SQLITE_VERSION 92 #endif 93 #ifdef SQLITE_VERSION_NUMBER 94 # undef SQLITE_VERSION_NUMBER 95 #endif 96 97 /* 98 ** CAPI3REF: Compile-Time Library Version Numbers 99 ** 100 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 101 ** evaluates to a string literal that is the SQLite version in the 102 ** format "X.Y.Z" where X is the major version number (always 3 for 103 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 104 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 105 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 106 ** numbers used in [SQLITE_VERSION].)^ 107 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 108 ** be larger than the release from which it is derived. Either Y will 109 ** be held constant and Z will be incremented or else Y will be incremented 110 ** and Z will be reset to zero. 111 ** 112 ** Since [version 3.6.18] ([dateof:3.6.18]), 113 ** SQLite source code has been stored in the 114 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 115 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 116 ** a string which identifies a particular check-in of SQLite 117 ** within its configuration management system. ^The SQLITE_SOURCE_ID 118 ** string contains the date and time of the check-in (UTC) and a SHA1 119 ** or SHA3-256 hash of the entire source tree. If the source code has 120 ** been edited in any way since it was last checked in, then the last 121 ** four hexadecimal digits of the hash may be modified. 122 ** 123 ** See also: [sqlite3_libversion()], 124 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 125 ** [sqlite_version()] and [sqlite_source_id()]. 126 */ 127 #define SQLITE_VERSION "3.21.0" 128 #define SQLITE_VERSION_NUMBER 3021000 129 #define SQLITE_SOURCE_ID "2017-10-24 18:55:49 1a584e499906b5c87ec7d43d4abce641fdf017c42125b083109bc77c4de48827" 130 131 /* 132 ** CAPI3REF: Run-Time Library Version Numbers 133 ** KEYWORDS: sqlite3_version sqlite3_sourceid 134 ** 135 ** These interfaces provide the same information as the [SQLITE_VERSION], 136 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 137 ** but are associated with the library instead of the header file. ^(Cautious 138 ** programmers might include assert() statements in their application to 139 ** verify that values returned by these interfaces match the macros in 140 ** the header, and thus ensure that the application is 141 ** compiled with matching library and header files. 142 ** 143 ** <blockquote><pre> 144 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 145 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 146 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 147 ** </pre></blockquote>)^ 148 ** 149 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 150 ** macro. ^The sqlite3_libversion() function returns a pointer to the 151 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 152 ** function is provided for use in DLLs since DLL users usually do not have 153 ** direct access to string constants within the DLL. ^The 154 ** sqlite3_libversion_number() function returns an integer equal to 155 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 156 ** a pointer to a string constant whose value is the same as the 157 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 158 ** using an edited copy of [the amalgamation], then the last four characters 159 ** of the hash might be different from [SQLITE_SOURCE_ID].)^ 160 ** 161 ** See also: [sqlite_version()] and [sqlite_source_id()]. 162 */ 163 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 164 SQLITE_API const char *sqlite3_libversion(void); 165 SQLITE_API const char *sqlite3_sourceid(void); 166 SQLITE_API int sqlite3_libversion_number(void); 167 168 /* 169 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 170 ** 171 ** ^The sqlite3_compileoption_used() function returns 0 or 1 172 ** indicating whether the specified option was defined at 173 ** compile time. ^The SQLITE_ prefix may be omitted from the 174 ** option name passed to sqlite3_compileoption_used(). 175 ** 176 ** ^The sqlite3_compileoption_get() function allows iterating 177 ** over the list of options that were defined at compile time by 178 ** returning the N-th compile time option string. ^If N is out of range, 179 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 180 ** prefix is omitted from any strings returned by 181 ** sqlite3_compileoption_get(). 182 ** 183 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 184 ** and sqlite3_compileoption_get() may be omitted by specifying the 185 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 186 ** 187 ** See also: SQL functions [sqlite_compileoption_used()] and 188 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 189 */ 190 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 191 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 192 SQLITE_API const char *sqlite3_compileoption_get(int N); 193 #endif 194 195 /* 196 ** CAPI3REF: Test To See If The Library Is Threadsafe 197 ** 198 ** ^The sqlite3_threadsafe() function returns zero if and only if 199 ** SQLite was compiled with mutexing code omitted due to the 200 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 201 ** 202 ** SQLite can be compiled with or without mutexes. When 203 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 204 ** are enabled and SQLite is threadsafe. When the 205 ** [SQLITE_THREADSAFE] macro is 0, 206 ** the mutexes are omitted. Without the mutexes, it is not safe 207 ** to use SQLite concurrently from more than one thread. 208 ** 209 ** Enabling mutexes incurs a measurable performance penalty. 210 ** So if speed is of utmost importance, it makes sense to disable 211 ** the mutexes. But for maximum safety, mutexes should be enabled. 212 ** ^The default behavior is for mutexes to be enabled. 213 ** 214 ** This interface can be used by an application to make sure that the 215 ** version of SQLite that it is linking against was compiled with 216 ** the desired setting of the [SQLITE_THREADSAFE] macro. 217 ** 218 ** This interface only reports on the compile-time mutex setting 219 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 220 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 221 ** can be fully or partially disabled using a call to [sqlite3_config()] 222 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 223 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 224 ** sqlite3_threadsafe() function shows only the compile-time setting of 225 ** thread safety, not any run-time changes to that setting made by 226 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 227 ** is unchanged by calls to sqlite3_config().)^ 228 ** 229 ** See the [threading mode] documentation for additional information. 230 */ 231 SQLITE_API int sqlite3_threadsafe(void); 232 233 /* 234 ** CAPI3REF: Database Connection Handle 235 ** KEYWORDS: {database connection} {database connections} 236 ** 237 ** Each open SQLite database is represented by a pointer to an instance of 238 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 239 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 240 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 241 ** and [sqlite3_close_v2()] are its destructors. There are many other 242 ** interfaces (such as 243 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 244 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 245 ** sqlite3 object. 246 */ 247 typedef struct sqlite3 sqlite3; 248 249 /* 250 ** CAPI3REF: 64-Bit Integer Types 251 ** KEYWORDS: sqlite_int64 sqlite_uint64 252 ** 253 ** Because there is no cross-platform way to specify 64-bit integer types 254 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 255 ** 256 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 257 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 258 ** compatibility only. 259 ** 260 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 261 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 262 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 263 ** between 0 and +18446744073709551615 inclusive. 264 */ 265 #ifdef SQLITE_INT64_TYPE 266 typedef SQLITE_INT64_TYPE sqlite_int64; 267 # ifdef SQLITE_UINT64_TYPE 268 typedef SQLITE_UINT64_TYPE sqlite_uint64; 269 # else 270 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 271 # endif 272 #elif defined(_MSC_VER) || defined(__BORLANDC__) 273 typedef __int64 sqlite_int64; 274 typedef unsigned __int64 sqlite_uint64; 275 #else 276 typedef long long int sqlite_int64; 277 typedef unsigned long long int sqlite_uint64; 278 #endif 279 typedef sqlite_int64 sqlite3_int64; 280 typedef sqlite_uint64 sqlite3_uint64; 281 282 /* 283 ** If compiling for a processor that lacks floating point support, 284 ** substitute integer for floating-point. 285 */ 286 #ifdef SQLITE_OMIT_FLOATING_POINT 287 # define double sqlite3_int64 288 #endif 289 290 /* 291 ** CAPI3REF: Closing A Database Connection 292 ** DESTRUCTOR: sqlite3 293 ** 294 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 295 ** for the [sqlite3] object. 296 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 297 ** the [sqlite3] object is successfully destroyed and all associated 298 ** resources are deallocated. 299 ** 300 ** ^If the database connection is associated with unfinalized prepared 301 ** statements or unfinished sqlite3_backup objects then sqlite3_close() 302 ** will leave the database connection open and return [SQLITE_BUSY]. 303 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements 304 ** and/or unfinished sqlite3_backups, then the database connection becomes 305 ** an unusable "zombie" which will automatically be deallocated when the 306 ** last prepared statement is finalized or the last sqlite3_backup is 307 ** finished. The sqlite3_close_v2() interface is intended for use with 308 ** host languages that are garbage collected, and where the order in which 309 ** destructors are called is arbitrary. 310 ** 311 ** Applications should [sqlite3_finalize | finalize] all [prepared statements], 312 ** [sqlite3_blob_close | close] all [BLOB handles], and 313 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 314 ** with the [sqlite3] object prior to attempting to close the object. ^If 315 ** sqlite3_close_v2() is called on a [database connection] that still has 316 ** outstanding [prepared statements], [BLOB handles], and/or 317 ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 318 ** of resources is deferred until all [prepared statements], [BLOB handles], 319 ** and [sqlite3_backup] objects are also destroyed. 320 ** 321 ** ^If an [sqlite3] object is destroyed while a transaction is open, 322 ** the transaction is automatically rolled back. 323 ** 324 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 325 ** must be either a NULL 326 ** pointer or an [sqlite3] object pointer obtained 327 ** from [sqlite3_open()], [sqlite3_open16()], or 328 ** [sqlite3_open_v2()], and not previously closed. 329 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 330 ** argument is a harmless no-op. 331 */ 332 SQLITE_API int sqlite3_close(sqlite3*); 333 SQLITE_API int sqlite3_close_v2(sqlite3*); 334 335 /* 336 ** The type for a callback function. 337 ** This is legacy and deprecated. It is included for historical 338 ** compatibility and is not documented. 339 */ 340 typedef int (*sqlite3_callback)(void*,int,char**, char**); 341 342 /* 343 ** CAPI3REF: One-Step Query Execution Interface 344 ** METHOD: sqlite3 345 ** 346 ** The sqlite3_exec() interface is a convenience wrapper around 347 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 348 ** that allows an application to run multiple statements of SQL 349 ** without having to use a lot of C code. 350 ** 351 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 352 ** semicolon-separate SQL statements passed into its 2nd argument, 353 ** in the context of the [database connection] passed in as its 1st 354 ** argument. ^If the callback function of the 3rd argument to 355 ** sqlite3_exec() is not NULL, then it is invoked for each result row 356 ** coming out of the evaluated SQL statements. ^The 4th argument to 357 ** sqlite3_exec() is relayed through to the 1st argument of each 358 ** callback invocation. ^If the callback pointer to sqlite3_exec() 359 ** is NULL, then no callback is ever invoked and result rows are 360 ** ignored. 361 ** 362 ** ^If an error occurs while evaluating the SQL statements passed into 363 ** sqlite3_exec(), then execution of the current statement stops and 364 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 365 ** is not NULL then any error message is written into memory obtained 366 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 367 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 368 ** on error message strings returned through the 5th parameter of 369 ** sqlite3_exec() after the error message string is no longer needed. 370 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 371 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 372 ** NULL before returning. 373 ** 374 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 375 ** routine returns SQLITE_ABORT without invoking the callback again and 376 ** without running any subsequent SQL statements. 377 ** 378 ** ^The 2nd argument to the sqlite3_exec() callback function is the 379 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 380 ** callback is an array of pointers to strings obtained as if from 381 ** [sqlite3_column_text()], one for each column. ^If an element of a 382 ** result row is NULL then the corresponding string pointer for the 383 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 384 ** sqlite3_exec() callback is an array of pointers to strings where each 385 ** entry represents the name of corresponding result column as obtained 386 ** from [sqlite3_column_name()]. 387 ** 388 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 389 ** to an empty string, or a pointer that contains only whitespace and/or 390 ** SQL comments, then no SQL statements are evaluated and the database 391 ** is not changed. 392 ** 393 ** Restrictions: 394 ** 395 ** <ul> 396 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 397 ** is a valid and open [database connection]. 398 ** <li> The application must not close the [database connection] specified by 399 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 400 ** <li> The application must not modify the SQL statement text passed into 401 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 402 ** </ul> 403 */ 404 SQLITE_API int sqlite3_exec( 405 sqlite3*, /* An open database */ 406 const char *sql, /* SQL to be evaluated */ 407 int (*callback)(void*,int,char**,char**), /* Callback function */ 408 void *, /* 1st argument to callback */ 409 char **errmsg /* Error msg written here */ 410 ); 411 412 /* 413 ** CAPI3REF: Result Codes 414 ** KEYWORDS: {result code definitions} 415 ** 416 ** Many SQLite functions return an integer result code from the set shown 417 ** here in order to indicate success or failure. 418 ** 419 ** New error codes may be added in future versions of SQLite. 420 ** 421 ** See also: [extended result code definitions] 422 */ 423 #define SQLITE_OK 0 /* Successful result */ 424 /* beginning-of-error-codes */ 425 #define SQLITE_ERROR 1 /* Generic error */ 426 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 427 #define SQLITE_PERM 3 /* Access permission denied */ 428 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 429 #define SQLITE_BUSY 5 /* The database file is locked */ 430 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 431 #define SQLITE_NOMEM 7 /* A malloc() failed */ 432 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 433 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 434 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 435 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 436 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 437 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 438 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 439 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 440 #define SQLITE_EMPTY 16 /* Internal use only */ 441 #define SQLITE_SCHEMA 17 /* The database schema changed */ 442 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 443 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 444 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 445 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 446 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 447 #define SQLITE_AUTH 23 /* Authorization denied */ 448 #define SQLITE_FORMAT 24 /* Not used */ 449 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 450 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 451 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 452 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 453 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 454 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 455 /* end-of-error-codes */ 456 457 /* 458 ** CAPI3REF: Extended Result Codes 459 ** KEYWORDS: {extended result code definitions} 460 ** 461 ** In its default configuration, SQLite API routines return one of 30 integer 462 ** [result codes]. However, experience has shown that many of 463 ** these result codes are too coarse-grained. They do not provide as 464 ** much information about problems as programmers might like. In an effort to 465 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 466 ** and later) include 467 ** support for additional result codes that provide more detailed information 468 ** about errors. These [extended result codes] are enabled or disabled 469 ** on a per database connection basis using the 470 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 471 ** the most recent error can be obtained using 472 ** [sqlite3_extended_errcode()]. 473 */ 474 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 475 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 476 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 477 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 478 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 479 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 480 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 481 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 482 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 483 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 484 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 485 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 486 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 487 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 488 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 489 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 490 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 491 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 492 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 493 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 494 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 495 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 496 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 497 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 498 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 499 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 500 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 501 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 502 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 503 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 504 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 505 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 506 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 507 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 508 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 509 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 510 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 511 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 512 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 513 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 514 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 515 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 516 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 517 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 518 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 519 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 520 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 521 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 522 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 523 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 524 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 525 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 526 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 527 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 528 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 529 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 530 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 531 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 532 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 533 534 /* 535 ** CAPI3REF: Flags For File Open Operations 536 ** 537 ** These bit values are intended for use in the 538 ** 3rd parameter to the [sqlite3_open_v2()] interface and 539 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 540 */ 541 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 542 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 543 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 544 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 545 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 546 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 547 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 548 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 549 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 550 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 551 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 552 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 553 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 554 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 555 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 556 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 557 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 558 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 559 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 560 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 561 562 /* Reserved: 0x00F00000 */ 563 564 /* 565 ** CAPI3REF: Device Characteristics 566 ** 567 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 568 ** object returns an integer which is a vector of these 569 ** bit values expressing I/O characteristics of the mass storage 570 ** device that holds the file that the [sqlite3_io_methods] 571 ** refers to. 572 ** 573 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 574 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 575 ** mean that writes of blocks that are nnn bytes in size and 576 ** are aligned to an address which is an integer multiple of 577 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 578 ** that when data is appended to a file, the data is appended 579 ** first then the size of the file is extended, never the other 580 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 581 ** information is written to disk in the same order as calls 582 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 583 ** after reboot following a crash or power loss, the only bytes in a 584 ** file that were written at the application level might have changed 585 ** and that adjacent bytes, even bytes within the same sector are 586 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 587 ** flag indicates that a file cannot be deleted when open. The 588 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 589 ** read-only media and cannot be changed even by processes with 590 ** elevated privileges. 591 ** 592 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 593 ** filesystem supports doing multiple write operations atomically when those 594 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 595 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 596 */ 597 #define SQLITE_IOCAP_ATOMIC 0x00000001 598 #define SQLITE_IOCAP_ATOMIC512 0x00000002 599 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 600 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 601 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 602 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 603 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 604 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 605 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 606 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 607 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 608 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 609 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 610 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 611 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 612 613 /* 614 ** CAPI3REF: File Locking Levels 615 ** 616 ** SQLite uses one of these integer values as the second 617 ** argument to calls it makes to the xLock() and xUnlock() methods 618 ** of an [sqlite3_io_methods] object. 619 */ 620 #define SQLITE_LOCK_NONE 0 621 #define SQLITE_LOCK_SHARED 1 622 #define SQLITE_LOCK_RESERVED 2 623 #define SQLITE_LOCK_PENDING 3 624 #define SQLITE_LOCK_EXCLUSIVE 4 625 626 /* 627 ** CAPI3REF: Synchronization Type Flags 628 ** 629 ** When SQLite invokes the xSync() method of an 630 ** [sqlite3_io_methods] object it uses a combination of 631 ** these integer values as the second argument. 632 ** 633 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 634 ** sync operation only needs to flush data to mass storage. Inode 635 ** information need not be flushed. If the lower four bits of the flag 636 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 637 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 638 ** to use Mac OS X style fullsync instead of fsync(). 639 ** 640 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 641 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 642 ** settings. The [synchronous pragma] determines when calls to the 643 ** xSync VFS method occur and applies uniformly across all platforms. 644 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 645 ** energetic or rigorous or forceful the sync operations are and 646 ** only make a difference on Mac OSX for the default SQLite code. 647 ** (Third-party VFS implementations might also make the distinction 648 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 649 ** operating systems natively supported by SQLite, only Mac OSX 650 ** cares about the difference.) 651 */ 652 #define SQLITE_SYNC_NORMAL 0x00002 653 #define SQLITE_SYNC_FULL 0x00003 654 #define SQLITE_SYNC_DATAONLY 0x00010 655 656 /* 657 ** CAPI3REF: OS Interface Open File Handle 658 ** 659 ** An [sqlite3_file] object represents an open file in the 660 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 661 ** implementations will 662 ** want to subclass this object by appending additional fields 663 ** for their own use. The pMethods entry is a pointer to an 664 ** [sqlite3_io_methods] object that defines methods for performing 665 ** I/O operations on the open file. 666 */ 667 typedef struct sqlite3_file sqlite3_file; 668 struct sqlite3_file { 669 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 670 }; 671 672 /* 673 ** CAPI3REF: OS Interface File Virtual Methods Object 674 ** 675 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 676 ** [sqlite3_file] object (or, more commonly, a subclass of the 677 ** [sqlite3_file] object) with a pointer to an instance of this object. 678 ** This object defines the methods used to perform various operations 679 ** against the open file represented by the [sqlite3_file] object. 680 ** 681 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 682 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 683 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 684 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 685 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 686 ** to NULL. 687 ** 688 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 689 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 690 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 691 ** flag may be ORed in to indicate that only the data of the file 692 ** and not its inode needs to be synced. 693 ** 694 ** The integer values to xLock() and xUnlock() are one of 695 ** <ul> 696 ** <li> [SQLITE_LOCK_NONE], 697 ** <li> [SQLITE_LOCK_SHARED], 698 ** <li> [SQLITE_LOCK_RESERVED], 699 ** <li> [SQLITE_LOCK_PENDING], or 700 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 701 ** </ul> 702 ** xLock() increases the lock. xUnlock() decreases the lock. 703 ** The xCheckReservedLock() method checks whether any database connection, 704 ** either in this process or in some other process, is holding a RESERVED, 705 ** PENDING, or EXCLUSIVE lock on the file. It returns true 706 ** if such a lock exists and false otherwise. 707 ** 708 ** The xFileControl() method is a generic interface that allows custom 709 ** VFS implementations to directly control an open file using the 710 ** [sqlite3_file_control()] interface. The second "op" argument is an 711 ** integer opcode. The third argument is a generic pointer intended to 712 ** point to a structure that may contain arguments or space in which to 713 ** write return values. Potential uses for xFileControl() might be 714 ** functions to enable blocking locks with timeouts, to change the 715 ** locking strategy (for example to use dot-file locks), to inquire 716 ** about the status of a lock, or to break stale locks. The SQLite 717 ** core reserves all opcodes less than 100 for its own use. 718 ** A [file control opcodes | list of opcodes] less than 100 is available. 719 ** Applications that define a custom xFileControl method should use opcodes 720 ** greater than 100 to avoid conflicts. VFS implementations should 721 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 722 ** recognize. 723 ** 724 ** The xSectorSize() method returns the sector size of the 725 ** device that underlies the file. The sector size is the 726 ** minimum write that can be performed without disturbing 727 ** other bytes in the file. The xDeviceCharacteristics() 728 ** method returns a bit vector describing behaviors of the 729 ** underlying device: 730 ** 731 ** <ul> 732 ** <li> [SQLITE_IOCAP_ATOMIC] 733 ** <li> [SQLITE_IOCAP_ATOMIC512] 734 ** <li> [SQLITE_IOCAP_ATOMIC1K] 735 ** <li> [SQLITE_IOCAP_ATOMIC2K] 736 ** <li> [SQLITE_IOCAP_ATOMIC4K] 737 ** <li> [SQLITE_IOCAP_ATOMIC8K] 738 ** <li> [SQLITE_IOCAP_ATOMIC16K] 739 ** <li> [SQLITE_IOCAP_ATOMIC32K] 740 ** <li> [SQLITE_IOCAP_ATOMIC64K] 741 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 742 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 743 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 744 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 745 ** <li> [SQLITE_IOCAP_IMMUTABLE] 746 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 747 ** </ul> 748 ** 749 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 750 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 751 ** mean that writes of blocks that are nnn bytes in size and 752 ** are aligned to an address which is an integer multiple of 753 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 754 ** that when data is appended to a file, the data is appended 755 ** first then the size of the file is extended, never the other 756 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 757 ** information is written to disk in the same order as calls 758 ** to xWrite(). 759 ** 760 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 761 ** in the unread portions of the buffer with zeros. A VFS that 762 ** fails to zero-fill short reads might seem to work. However, 763 ** failure to zero-fill short reads will eventually lead to 764 ** database corruption. 765 */ 766 typedef struct sqlite3_io_methods sqlite3_io_methods; 767 struct sqlite3_io_methods { 768 int iVersion; 769 int (*xClose)(sqlite3_file*); 770 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 771 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 772 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 773 int (*xSync)(sqlite3_file*, int flags); 774 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 775 int (*xLock)(sqlite3_file*, int); 776 int (*xUnlock)(sqlite3_file*, int); 777 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 778 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 779 int (*xSectorSize)(sqlite3_file*); 780 int (*xDeviceCharacteristics)(sqlite3_file*); 781 /* Methods above are valid for version 1 */ 782 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 783 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 784 void (*xShmBarrier)(sqlite3_file*); 785 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 786 /* Methods above are valid for version 2 */ 787 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 788 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 789 /* Methods above are valid for version 3 */ 790 /* Additional methods may be added in future releases */ 791 }; 792 793 /* 794 ** CAPI3REF: Standard File Control Opcodes 795 ** KEYWORDS: {file control opcodes} {file control opcode} 796 ** 797 ** These integer constants are opcodes for the xFileControl method 798 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 799 ** interface. 800 ** 801 ** <ul> 802 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 803 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 804 ** opcode causes the xFileControl method to write the current state of 805 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 806 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 807 ** into an integer that the pArg argument points to. This capability 808 ** is used during testing and is only available when the SQLITE_TEST 809 ** compile-time option is used. 810 ** 811 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 812 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 813 ** layer a hint of how large the database file will grow to be during the 814 ** current transaction. This hint is not guaranteed to be accurate but it 815 ** is often close. The underlying VFS might choose to preallocate database 816 ** file space based on this hint in order to help writes to the database 817 ** file run faster. 818 ** 819 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 820 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 821 ** extends and truncates the database file in chunks of a size specified 822 ** by the user. The fourth argument to [sqlite3_file_control()] should 823 ** point to an integer (type int) containing the new chunk-size to use 824 ** for the nominated database. Allocating database file space in large 825 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 826 ** improve performance on some systems. 827 ** 828 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 829 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 830 ** to the [sqlite3_file] object associated with a particular database 831 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 832 ** 833 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 834 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 835 ** to the [sqlite3_file] object associated with the journal file (either 836 ** the [rollback journal] or the [write-ahead log]) for a particular database 837 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 838 ** 839 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 840 ** No longer in use. 841 ** 842 ** <li>[[SQLITE_FCNTL_SYNC]] 843 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 844 ** sent to the VFS immediately before the xSync method is invoked on a 845 ** database file descriptor. Or, if the xSync method is not invoked 846 ** because the user has configured SQLite with 847 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 848 ** of the xSync method. In most cases, the pointer argument passed with 849 ** this file-control is NULL. However, if the database file is being synced 850 ** as part of a multi-database commit, the argument points to a nul-terminated 851 ** string containing the transactions master-journal file name. VFSes that 852 ** do not need this signal should silently ignore this opcode. Applications 853 ** should not call [sqlite3_file_control()] with this opcode as doing so may 854 ** disrupt the operation of the specialized VFSes that do require it. 855 ** 856 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 857 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 858 ** and sent to the VFS after a transaction has been committed immediately 859 ** but before the database is unlocked. VFSes that do not need this signal 860 ** should silently ignore this opcode. Applications should not call 861 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 862 ** operation of the specialized VFSes that do require it. 863 ** 864 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 865 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 866 ** retry counts and intervals for certain disk I/O operations for the 867 ** windows [VFS] in order to provide robustness in the presence of 868 ** anti-virus programs. By default, the windows VFS will retry file read, 869 ** file write, and file delete operations up to 10 times, with a delay 870 ** of 25 milliseconds before the first retry and with the delay increasing 871 ** by an additional 25 milliseconds with each subsequent retry. This 872 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 873 ** to be adjusted. The values are changed for all database connections 874 ** within the same process. The argument is a pointer to an array of two 875 ** integers where the first integer is the new retry count and the second 876 ** integer is the delay. If either integer is negative, then the setting 877 ** is not changed but instead the prior value of that setting is written 878 ** into the array entry, allowing the current retry settings to be 879 ** interrogated. The zDbName parameter is ignored. 880 ** 881 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 882 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 883 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 884 ** write ahead log and shared memory files used for transaction control 885 ** are automatically deleted when the latest connection to the database 886 ** closes. Setting persistent WAL mode causes those files to persist after 887 ** close. Persisting the files is useful when other processes that do not 888 ** have write permission on the directory containing the database file want 889 ** to read the database file, as the WAL and shared memory files must exist 890 ** in order for the database to be readable. The fourth parameter to 891 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 892 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 893 ** WAL mode. If the integer is -1, then it is overwritten with the current 894 ** WAL persistence setting. 895 ** 896 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 897 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 898 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 899 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 900 ** xDeviceCharacteristics methods. The fourth parameter to 901 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 902 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 903 ** mode. If the integer is -1, then it is overwritten with the current 904 ** zero-damage mode setting. 905 ** 906 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 907 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 908 ** a write transaction to indicate that, unless it is rolled back for some 909 ** reason, the entire database file will be overwritten by the current 910 ** transaction. This is used by VACUUM operations. 911 ** 912 ** <li>[[SQLITE_FCNTL_VFSNAME]] 913 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 914 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 915 ** final bottom-level VFS are written into memory obtained from 916 ** [sqlite3_malloc()] and the result is stored in the char* variable 917 ** that the fourth parameter of [sqlite3_file_control()] points to. 918 ** The caller is responsible for freeing the memory when done. As with 919 ** all file-control actions, there is no guarantee that this will actually 920 ** do anything. Callers should initialize the char* variable to a NULL 921 ** pointer in case this file-control is not implemented. This file-control 922 ** is intended for diagnostic use only. 923 ** 924 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 925 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 926 ** [VFSes] currently in use. ^(The argument X in 927 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 928 ** of type "[sqlite3_vfs] **". This opcodes will set *X 929 ** to a pointer to the top-level VFS.)^ 930 ** ^When there are multiple VFS shims in the stack, this opcode finds the 931 ** upper-most shim only. 932 ** 933 ** <li>[[SQLITE_FCNTL_PRAGMA]] 934 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 935 ** file control is sent to the open [sqlite3_file] object corresponding 936 ** to the database file to which the pragma statement refers. ^The argument 937 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 938 ** pointers to strings (char**) in which the second element of the array 939 ** is the name of the pragma and the third element is the argument to the 940 ** pragma or NULL if the pragma has no argument. ^The handler for an 941 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 942 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 943 ** or the equivalent and that string will become the result of the pragma or 944 ** the error message if the pragma fails. ^If the 945 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 946 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 947 ** file control returns [SQLITE_OK], then the parser assumes that the 948 ** VFS has handled the PRAGMA itself and the parser generates a no-op 949 ** prepared statement if result string is NULL, or that returns a copy 950 ** of the result string if the string is non-NULL. 951 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 952 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 953 ** that the VFS encountered an error while handling the [PRAGMA] and the 954 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 955 ** file control occurs at the beginning of pragma statement analysis and so 956 ** it is able to override built-in [PRAGMA] statements. 957 ** 958 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 959 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 960 ** file-control may be invoked by SQLite on the database file handle 961 ** shortly after it is opened in order to provide a custom VFS with access 962 ** to the connections busy-handler callback. The argument is of type (void **) 963 ** - an array of two (void *) values. The first (void *) actually points 964 ** to a function of type (int (*)(void *)). In order to invoke the connections 965 ** busy-handler, this function should be invoked with the second (void *) in 966 ** the array as the only argument. If it returns non-zero, then the operation 967 ** should be retried. If it returns zero, the custom VFS should abandon the 968 ** current operation. 969 ** 970 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 971 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 972 ** to have SQLite generate a 973 ** temporary filename using the same algorithm that is followed to generate 974 ** temporary filenames for TEMP tables and other internal uses. The 975 ** argument should be a char** which will be filled with the filename 976 ** written into memory obtained from [sqlite3_malloc()]. The caller should 977 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 978 ** 979 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 980 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 981 ** maximum number of bytes that will be used for memory-mapped I/O. 982 ** The argument is a pointer to a value of type sqlite3_int64 that 983 ** is an advisory maximum number of bytes in the file to memory map. The 984 ** pointer is overwritten with the old value. The limit is not changed if 985 ** the value originally pointed to is negative, and so the current limit 986 ** can be queried by passing in a pointer to a negative number. This 987 ** file-control is used internally to implement [PRAGMA mmap_size]. 988 ** 989 ** <li>[[SQLITE_FCNTL_TRACE]] 990 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 991 ** to the VFS about what the higher layers of the SQLite stack are doing. 992 ** This file control is used by some VFS activity tracing [shims]. 993 ** The argument is a zero-terminated string. Higher layers in the 994 ** SQLite stack may generate instances of this file control if 995 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 996 ** 997 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 998 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 999 ** pointer to an integer and it writes a boolean into that integer depending 1000 ** on whether or not the file has been renamed, moved, or deleted since it 1001 ** was first opened. 1002 ** 1003 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1004 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1005 ** underlying native file handle associated with a file handle. This file 1006 ** control interprets its argument as a pointer to a native file handle and 1007 ** writes the resulting value there. 1008 ** 1009 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1010 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1011 ** opcode causes the xFileControl method to swap the file handle with the one 1012 ** pointed to by the pArg argument. This capability is used during testing 1013 ** and only needs to be supported when SQLITE_TEST is defined. 1014 ** 1015 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1016 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1017 ** be advantageous to block on the next WAL lock if the lock is not immediately 1018 ** available. The WAL subsystem issues this signal during rare 1019 ** circumstances in order to fix a problem with priority inversion. 1020 ** Applications should <em>not</em> use this file-control. 1021 ** 1022 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1023 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1024 ** VFS should return SQLITE_NOTFOUND for this opcode. 1025 ** 1026 ** <li>[[SQLITE_FCNTL_RBU]] 1027 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1028 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1029 ** this opcode. 1030 ** 1031 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1032 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1033 ** the file descriptor is placed in "batch write mode", which 1034 ** means all subsequent write operations will be deferred and done 1035 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1036 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1037 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1038 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1039 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1040 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1041 ** except for calls to the xWrite method and the xFileControl method 1042 ** with [SQLITE_FCNTL_SIZE_HINT]. 1043 ** 1044 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1045 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1046 ** operations since the previous successful call to 1047 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1048 ** This file control returns [SQLITE_OK] if and only if the writes were 1049 ** all performed successfully and have been committed to persistent storage. 1050 ** ^Regardless of whether or not it is successful, this file control takes 1051 ** the file descriptor out of batch write mode so that all subsequent 1052 ** write operations are independent. 1053 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1054 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1055 ** 1056 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1057 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1058 ** operations since the previous successful call to 1059 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1060 ** ^This file control takes the file descriptor out of batch write mode 1061 ** so that all subsequent write operations are independent. 1062 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1063 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1064 ** </ul> 1065 */ 1066 #define SQLITE_FCNTL_LOCKSTATE 1 1067 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1068 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1069 #define SQLITE_FCNTL_LAST_ERRNO 4 1070 #define SQLITE_FCNTL_SIZE_HINT 5 1071 #define SQLITE_FCNTL_CHUNK_SIZE 6 1072 #define SQLITE_FCNTL_FILE_POINTER 7 1073 #define SQLITE_FCNTL_SYNC_OMITTED 8 1074 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1075 #define SQLITE_FCNTL_PERSIST_WAL 10 1076 #define SQLITE_FCNTL_OVERWRITE 11 1077 #define SQLITE_FCNTL_VFSNAME 12 1078 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1079 #define SQLITE_FCNTL_PRAGMA 14 1080 #define SQLITE_FCNTL_BUSYHANDLER 15 1081 #define SQLITE_FCNTL_TEMPFILENAME 16 1082 #define SQLITE_FCNTL_MMAP_SIZE 18 1083 #define SQLITE_FCNTL_TRACE 19 1084 #define SQLITE_FCNTL_HAS_MOVED 20 1085 #define SQLITE_FCNTL_SYNC 21 1086 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1087 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1088 #define SQLITE_FCNTL_WAL_BLOCK 24 1089 #define SQLITE_FCNTL_ZIPVFS 25 1090 #define SQLITE_FCNTL_RBU 26 1091 #define SQLITE_FCNTL_VFS_POINTER 27 1092 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1093 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1094 #define SQLITE_FCNTL_PDB 30 1095 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1096 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1097 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1098 1099 /* deprecated names */ 1100 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1101 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1102 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1103 1104 1105 /* 1106 ** CAPI3REF: Mutex Handle 1107 ** 1108 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1109 ** abstract type for a mutex object. The SQLite core never looks 1110 ** at the internal representation of an [sqlite3_mutex]. It only 1111 ** deals with pointers to the [sqlite3_mutex] object. 1112 ** 1113 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1114 */ 1115 typedef struct sqlite3_mutex sqlite3_mutex; 1116 1117 /* 1118 ** CAPI3REF: Loadable Extension Thunk 1119 ** 1120 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1121 ** the third parameter to entry points of [loadable extensions]. This 1122 ** structure must be typedefed in order to work around compiler warnings 1123 ** on some platforms. 1124 */ 1125 typedef struct sqlite3_api_routines sqlite3_api_routines; 1126 1127 /* 1128 ** CAPI3REF: OS Interface Object 1129 ** 1130 ** An instance of the sqlite3_vfs object defines the interface between 1131 ** the SQLite core and the underlying operating system. The "vfs" 1132 ** in the name of the object stands for "virtual file system". See 1133 ** the [VFS | VFS documentation] for further information. 1134 ** 1135 ** The value of the iVersion field is initially 1 but may be larger in 1136 ** future versions of SQLite. Additional fields may be appended to this 1137 ** object when the iVersion value is increased. Note that the structure 1138 ** of the sqlite3_vfs object changes in the transaction between 1139 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1140 ** modified. 1141 ** 1142 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1143 ** structure used by this VFS. mxPathname is the maximum length of 1144 ** a pathname in this VFS. 1145 ** 1146 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1147 ** the pNext pointer. The [sqlite3_vfs_register()] 1148 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1149 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1150 ** searches the list. Neither the application code nor the VFS 1151 ** implementation should use the pNext pointer. 1152 ** 1153 ** The pNext field is the only field in the sqlite3_vfs 1154 ** structure that SQLite will ever modify. SQLite will only access 1155 ** or modify this field while holding a particular static mutex. 1156 ** The application should never modify anything within the sqlite3_vfs 1157 ** object once the object has been registered. 1158 ** 1159 ** The zName field holds the name of the VFS module. The name must 1160 ** be unique across all VFS modules. 1161 ** 1162 ** [[sqlite3_vfs.xOpen]] 1163 ** ^SQLite guarantees that the zFilename parameter to xOpen 1164 ** is either a NULL pointer or string obtained 1165 ** from xFullPathname() with an optional suffix added. 1166 ** ^If a suffix is added to the zFilename parameter, it will 1167 ** consist of a single "-" character followed by no more than 1168 ** 11 alphanumeric and/or "-" characters. 1169 ** ^SQLite further guarantees that 1170 ** the string will be valid and unchanged until xClose() is 1171 ** called. Because of the previous sentence, 1172 ** the [sqlite3_file] can safely store a pointer to the 1173 ** filename if it needs to remember the filename for some reason. 1174 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1175 ** must invent its own temporary name for the file. ^Whenever the 1176 ** xFilename parameter is NULL it will also be the case that the 1177 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1178 ** 1179 ** The flags argument to xOpen() includes all bits set in 1180 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1181 ** or [sqlite3_open16()] is used, then flags includes at least 1182 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1183 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1184 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1185 ** 1186 ** ^(SQLite will also add one of the following flags to the xOpen() 1187 ** call, depending on the object being opened: 1188 ** 1189 ** <ul> 1190 ** <li> [SQLITE_OPEN_MAIN_DB] 1191 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1192 ** <li> [SQLITE_OPEN_TEMP_DB] 1193 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1194 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1195 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1196 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1197 ** <li> [SQLITE_OPEN_WAL] 1198 ** </ul>)^ 1199 ** 1200 ** The file I/O implementation can use the object type flags to 1201 ** change the way it deals with files. For example, an application 1202 ** that does not care about crash recovery or rollback might make 1203 ** the open of a journal file a no-op. Writes to this journal would 1204 ** also be no-ops, and any attempt to read the journal would return 1205 ** SQLITE_IOERR. Or the implementation might recognize that a database 1206 ** file will be doing page-aligned sector reads and writes in a random 1207 ** order and set up its I/O subsystem accordingly. 1208 ** 1209 ** SQLite might also add one of the following flags to the xOpen method: 1210 ** 1211 ** <ul> 1212 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1213 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1214 ** </ul> 1215 ** 1216 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1217 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1218 ** will be set for TEMP databases and their journals, transient 1219 ** databases, and subjournals. 1220 ** 1221 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1222 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1223 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1224 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1225 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1226 ** be created, and that it is an error if it already exists. 1227 ** It is <i>not</i> used to indicate the file should be opened 1228 ** for exclusive access. 1229 ** 1230 ** ^At least szOsFile bytes of memory are allocated by SQLite 1231 ** to hold the [sqlite3_file] structure passed as the third 1232 ** argument to xOpen. The xOpen method does not have to 1233 ** allocate the structure; it should just fill it in. Note that 1234 ** the xOpen method must set the sqlite3_file.pMethods to either 1235 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1236 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1237 ** element will be valid after xOpen returns regardless of the success 1238 ** or failure of the xOpen call. 1239 ** 1240 ** [[sqlite3_vfs.xAccess]] 1241 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1242 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1243 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1244 ** to test whether a file is at least readable. The file can be a 1245 ** directory. 1246 ** 1247 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1248 ** output buffer xFullPathname. The exact size of the output buffer 1249 ** is also passed as a parameter to both methods. If the output buffer 1250 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1251 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1252 ** to prevent this by setting mxPathname to a sufficiently large value. 1253 ** 1254 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1255 ** interfaces are not strictly a part of the filesystem, but they are 1256 ** included in the VFS structure for completeness. 1257 ** The xRandomness() function attempts to return nBytes bytes 1258 ** of good-quality randomness into zOut. The return value is 1259 ** the actual number of bytes of randomness obtained. 1260 ** The xSleep() method causes the calling thread to sleep for at 1261 ** least the number of microseconds given. ^The xCurrentTime() 1262 ** method returns a Julian Day Number for the current date and time as 1263 ** a floating point value. 1264 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1265 ** Day Number multiplied by 86400000 (the number of milliseconds in 1266 ** a 24-hour day). 1267 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1268 ** date and time if that method is available (if iVersion is 2 or 1269 ** greater and the function pointer is not NULL) and will fall back 1270 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1271 ** 1272 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1273 ** are not used by the SQLite core. These optional interfaces are provided 1274 ** by some VFSes to facilitate testing of the VFS code. By overriding 1275 ** system calls with functions under its control, a test program can 1276 ** simulate faults and error conditions that would otherwise be difficult 1277 ** or impossible to induce. The set of system calls that can be overridden 1278 ** varies from one VFS to another, and from one version of the same VFS to the 1279 ** next. Applications that use these interfaces must be prepared for any 1280 ** or all of these interfaces to be NULL or for their behavior to change 1281 ** from one release to the next. Applications must not attempt to access 1282 ** any of these methods if the iVersion of the VFS is less than 3. 1283 */ 1284 typedef struct sqlite3_vfs sqlite3_vfs; 1285 typedef void (*sqlite3_syscall_ptr)(void); 1286 struct sqlite3_vfs { 1287 int iVersion; /* Structure version number (currently 3) */ 1288 int szOsFile; /* Size of subclassed sqlite3_file */ 1289 int mxPathname; /* Maximum file pathname length */ 1290 sqlite3_vfs *pNext; /* Next registered VFS */ 1291 const char *zName; /* Name of this virtual file system */ 1292 void *pAppData; /* Pointer to application-specific data */ 1293 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1294 int flags, int *pOutFlags); 1295 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1296 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1297 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1298 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1299 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1300 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1301 void (*xDlClose)(sqlite3_vfs*, void*); 1302 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1303 int (*xSleep)(sqlite3_vfs*, int microseconds); 1304 int (*xCurrentTime)(sqlite3_vfs*, double*); 1305 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1306 /* 1307 ** The methods above are in version 1 of the sqlite_vfs object 1308 ** definition. Those that follow are added in version 2 or later 1309 */ 1310 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1311 /* 1312 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1313 ** Those below are for version 3 and greater. 1314 */ 1315 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1316 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1317 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1318 /* 1319 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1320 ** New fields may be appended in future versions. The iVersion 1321 ** value will increment whenever this happens. 1322 */ 1323 }; 1324 1325 /* 1326 ** CAPI3REF: Flags for the xAccess VFS method 1327 ** 1328 ** These integer constants can be used as the third parameter to 1329 ** the xAccess method of an [sqlite3_vfs] object. They determine 1330 ** what kind of permissions the xAccess method is looking for. 1331 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1332 ** simply checks whether the file exists. 1333 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1334 ** checks whether the named directory is both readable and writable 1335 ** (in other words, if files can be added, removed, and renamed within 1336 ** the directory). 1337 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1338 ** [temp_store_directory pragma], though this could change in a future 1339 ** release of SQLite. 1340 ** With SQLITE_ACCESS_READ, the xAccess method 1341 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1342 ** currently unused, though it might be used in a future release of 1343 ** SQLite. 1344 */ 1345 #define SQLITE_ACCESS_EXISTS 0 1346 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1347 #define SQLITE_ACCESS_READ 2 /* Unused */ 1348 1349 /* 1350 ** CAPI3REF: Flags for the xShmLock VFS method 1351 ** 1352 ** These integer constants define the various locking operations 1353 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1354 ** following are the only legal combinations of flags to the 1355 ** xShmLock method: 1356 ** 1357 ** <ul> 1358 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1359 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1360 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1361 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1362 ** </ul> 1363 ** 1364 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1365 ** was given on the corresponding lock. 1366 ** 1367 ** The xShmLock method can transition between unlocked and SHARED or 1368 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1369 ** and EXCLUSIVE. 1370 */ 1371 #define SQLITE_SHM_UNLOCK 1 1372 #define SQLITE_SHM_LOCK 2 1373 #define SQLITE_SHM_SHARED 4 1374 #define SQLITE_SHM_EXCLUSIVE 8 1375 1376 /* 1377 ** CAPI3REF: Maximum xShmLock index 1378 ** 1379 ** The xShmLock method on [sqlite3_io_methods] may use values 1380 ** between 0 and this upper bound as its "offset" argument. 1381 ** The SQLite core will never attempt to acquire or release a 1382 ** lock outside of this range 1383 */ 1384 #define SQLITE_SHM_NLOCK 8 1385 1386 1387 /* 1388 ** CAPI3REF: Initialize The SQLite Library 1389 ** 1390 ** ^The sqlite3_initialize() routine initializes the 1391 ** SQLite library. ^The sqlite3_shutdown() routine 1392 ** deallocates any resources that were allocated by sqlite3_initialize(). 1393 ** These routines are designed to aid in process initialization and 1394 ** shutdown on embedded systems. Workstation applications using 1395 ** SQLite normally do not need to invoke either of these routines. 1396 ** 1397 ** A call to sqlite3_initialize() is an "effective" call if it is 1398 ** the first time sqlite3_initialize() is invoked during the lifetime of 1399 ** the process, or if it is the first time sqlite3_initialize() is invoked 1400 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1401 ** of sqlite3_initialize() does any initialization. All other calls 1402 ** are harmless no-ops.)^ 1403 ** 1404 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1405 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1406 ** an effective call to sqlite3_shutdown() does any deinitialization. 1407 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1408 ** 1409 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1410 ** is not. The sqlite3_shutdown() interface must only be called from a 1411 ** single thread. All open [database connections] must be closed and all 1412 ** other SQLite resources must be deallocated prior to invoking 1413 ** sqlite3_shutdown(). 1414 ** 1415 ** Among other things, ^sqlite3_initialize() will invoke 1416 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1417 ** will invoke sqlite3_os_end(). 1418 ** 1419 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1420 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1421 ** the library (perhaps it is unable to allocate a needed resource such 1422 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1423 ** 1424 ** ^The sqlite3_initialize() routine is called internally by many other 1425 ** SQLite interfaces so that an application usually does not need to 1426 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1427 ** calls sqlite3_initialize() so the SQLite library will be automatically 1428 ** initialized when [sqlite3_open()] is called if it has not be initialized 1429 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1430 ** compile-time option, then the automatic calls to sqlite3_initialize() 1431 ** are omitted and the application must call sqlite3_initialize() directly 1432 ** prior to using any other SQLite interface. For maximum portability, 1433 ** it is recommended that applications always invoke sqlite3_initialize() 1434 ** directly prior to using any other SQLite interface. Future releases 1435 ** of SQLite may require this. In other words, the behavior exhibited 1436 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1437 ** default behavior in some future release of SQLite. 1438 ** 1439 ** The sqlite3_os_init() routine does operating-system specific 1440 ** initialization of the SQLite library. The sqlite3_os_end() 1441 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1442 ** performed by these routines include allocation or deallocation 1443 ** of static resources, initialization of global variables, 1444 ** setting up a default [sqlite3_vfs] module, or setting up 1445 ** a default configuration using [sqlite3_config()]. 1446 ** 1447 ** The application should never invoke either sqlite3_os_init() 1448 ** or sqlite3_os_end() directly. The application should only invoke 1449 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1450 ** interface is called automatically by sqlite3_initialize() and 1451 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1452 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1453 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1454 ** When [custom builds | built for other platforms] 1455 ** (using the [SQLITE_OS_OTHER=1] compile-time 1456 ** option) the application must supply a suitable implementation for 1457 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1458 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1459 ** must return [SQLITE_OK] on success and some other [error code] upon 1460 ** failure. 1461 */ 1462 SQLITE_API int sqlite3_initialize(void); 1463 SQLITE_API int sqlite3_shutdown(void); 1464 SQLITE_API int sqlite3_os_init(void); 1465 SQLITE_API int sqlite3_os_end(void); 1466 1467 /* 1468 ** CAPI3REF: Configuring The SQLite Library 1469 ** 1470 ** The sqlite3_config() interface is used to make global configuration 1471 ** changes to SQLite in order to tune SQLite to the specific needs of 1472 ** the application. The default configuration is recommended for most 1473 ** applications and so this routine is usually not necessary. It is 1474 ** provided to support rare applications with unusual needs. 1475 ** 1476 ** <b>The sqlite3_config() interface is not threadsafe. The application 1477 ** must ensure that no other SQLite interfaces are invoked by other 1478 ** threads while sqlite3_config() is running.</b> 1479 ** 1480 ** The sqlite3_config() interface 1481 ** may only be invoked prior to library initialization using 1482 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1483 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1484 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1485 ** Note, however, that ^sqlite3_config() can be called as part of the 1486 ** implementation of an application-defined [sqlite3_os_init()]. 1487 ** 1488 ** The first argument to sqlite3_config() is an integer 1489 ** [configuration option] that determines 1490 ** what property of SQLite is to be configured. Subsequent arguments 1491 ** vary depending on the [configuration option] 1492 ** in the first argument. 1493 ** 1494 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1495 ** ^If the option is unknown or SQLite is unable to set the option 1496 ** then this routine returns a non-zero [error code]. 1497 */ 1498 SQLITE_API int sqlite3_config(int, ...); 1499 1500 /* 1501 ** CAPI3REF: Configure database connections 1502 ** METHOD: sqlite3 1503 ** 1504 ** The sqlite3_db_config() interface is used to make configuration 1505 ** changes to a [database connection]. The interface is similar to 1506 ** [sqlite3_config()] except that the changes apply to a single 1507 ** [database connection] (specified in the first argument). 1508 ** 1509 ** The second argument to sqlite3_db_config(D,V,...) is the 1510 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1511 ** that indicates what aspect of the [database connection] is being configured. 1512 ** Subsequent arguments vary depending on the configuration verb. 1513 ** 1514 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1515 ** the call is considered successful. 1516 */ 1517 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1518 1519 /* 1520 ** CAPI3REF: Memory Allocation Routines 1521 ** 1522 ** An instance of this object defines the interface between SQLite 1523 ** and low-level memory allocation routines. 1524 ** 1525 ** This object is used in only one place in the SQLite interface. 1526 ** A pointer to an instance of this object is the argument to 1527 ** [sqlite3_config()] when the configuration option is 1528 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1529 ** By creating an instance of this object 1530 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1531 ** during configuration, an application can specify an alternative 1532 ** memory allocation subsystem for SQLite to use for all of its 1533 ** dynamic memory needs. 1534 ** 1535 ** Note that SQLite comes with several [built-in memory allocators] 1536 ** that are perfectly adequate for the overwhelming majority of applications 1537 ** and that this object is only useful to a tiny minority of applications 1538 ** with specialized memory allocation requirements. This object is 1539 ** also used during testing of SQLite in order to specify an alternative 1540 ** memory allocator that simulates memory out-of-memory conditions in 1541 ** order to verify that SQLite recovers gracefully from such 1542 ** conditions. 1543 ** 1544 ** The xMalloc, xRealloc, and xFree methods must work like the 1545 ** malloc(), realloc() and free() functions from the standard C library. 1546 ** ^SQLite guarantees that the second argument to 1547 ** xRealloc is always a value returned by a prior call to xRoundup. 1548 ** 1549 ** xSize should return the allocated size of a memory allocation 1550 ** previously obtained from xMalloc or xRealloc. The allocated size 1551 ** is always at least as big as the requested size but may be larger. 1552 ** 1553 ** The xRoundup method returns what would be the allocated size of 1554 ** a memory allocation given a particular requested size. Most memory 1555 ** allocators round up memory allocations at least to the next multiple 1556 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1557 ** Every memory allocation request coming in through [sqlite3_malloc()] 1558 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1559 ** that causes the corresponding memory allocation to fail. 1560 ** 1561 ** The xInit method initializes the memory allocator. For example, 1562 ** it might allocate any require mutexes or initialize internal data 1563 ** structures. The xShutdown method is invoked (indirectly) by 1564 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1565 ** by xInit. The pAppData pointer is used as the only parameter to 1566 ** xInit and xShutdown. 1567 ** 1568 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1569 ** the xInit method, so the xInit method need not be threadsafe. The 1570 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1571 ** not need to be threadsafe either. For all other methods, SQLite 1572 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1573 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1574 ** it is by default) and so the methods are automatically serialized. 1575 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1576 ** methods must be threadsafe or else make their own arrangements for 1577 ** serialization. 1578 ** 1579 ** SQLite will never invoke xInit() more than once without an intervening 1580 ** call to xShutdown(). 1581 */ 1582 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1583 struct sqlite3_mem_methods { 1584 void *(*xMalloc)(int); /* Memory allocation function */ 1585 void (*xFree)(void*); /* Free a prior allocation */ 1586 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1587 int (*xSize)(void*); /* Return the size of an allocation */ 1588 int (*xRoundup)(int); /* Round up request size to allocation size */ 1589 int (*xInit)(void*); /* Initialize the memory allocator */ 1590 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1591 void *pAppData; /* Argument to xInit() and xShutdown() */ 1592 }; 1593 1594 /* 1595 ** CAPI3REF: Configuration Options 1596 ** KEYWORDS: {configuration option} 1597 ** 1598 ** These constants are the available integer configuration options that 1599 ** can be passed as the first argument to the [sqlite3_config()] interface. 1600 ** 1601 ** New configuration options may be added in future releases of SQLite. 1602 ** Existing configuration options might be discontinued. Applications 1603 ** should check the return code from [sqlite3_config()] to make sure that 1604 ** the call worked. The [sqlite3_config()] interface will return a 1605 ** non-zero [error code] if a discontinued or unsupported configuration option 1606 ** is invoked. 1607 ** 1608 ** <dl> 1609 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1610 ** <dd>There are no arguments to this option. ^This option sets the 1611 ** [threading mode] to Single-thread. In other words, it disables 1612 ** all mutexing and puts SQLite into a mode where it can only be used 1613 ** by a single thread. ^If SQLite is compiled with 1614 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1615 ** it is not possible to change the [threading mode] from its default 1616 ** value of Single-thread and so [sqlite3_config()] will return 1617 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1618 ** configuration option.</dd> 1619 ** 1620 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1621 ** <dd>There are no arguments to this option. ^This option sets the 1622 ** [threading mode] to Multi-thread. In other words, it disables 1623 ** mutexing on [database connection] and [prepared statement] objects. 1624 ** The application is responsible for serializing access to 1625 ** [database connections] and [prepared statements]. But other mutexes 1626 ** are enabled so that SQLite will be safe to use in a multi-threaded 1627 ** environment as long as no two threads attempt to use the same 1628 ** [database connection] at the same time. ^If SQLite is compiled with 1629 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1630 ** it is not possible to set the Multi-thread [threading mode] and 1631 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1632 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1633 ** 1634 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1635 ** <dd>There are no arguments to this option. ^This option sets the 1636 ** [threading mode] to Serialized. In other words, this option enables 1637 ** all mutexes including the recursive 1638 ** mutexes on [database connection] and [prepared statement] objects. 1639 ** In this mode (which is the default when SQLite is compiled with 1640 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1641 ** to [database connections] and [prepared statements] so that the 1642 ** application is free to use the same [database connection] or the 1643 ** same [prepared statement] in different threads at the same time. 1644 ** ^If SQLite is compiled with 1645 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1646 ** it is not possible to set the Serialized [threading mode] and 1647 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1648 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1649 ** 1650 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1651 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1652 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1653 ** The argument specifies 1654 ** alternative low-level memory allocation routines to be used in place of 1655 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1656 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1657 ** before the [sqlite3_config()] call returns.</dd> 1658 ** 1659 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1660 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1661 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1662 ** The [sqlite3_mem_methods] 1663 ** structure is filled with the currently defined memory allocation routines.)^ 1664 ** This option can be used to overload the default memory allocation 1665 ** routines with a wrapper that simulations memory allocation failure or 1666 ** tracks memory usage, for example. </dd> 1667 ** 1668 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1669 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1670 ** type int, interpreted as a boolean, which if true provides a hint to 1671 ** SQLite that it should avoid large memory allocations if possible. 1672 ** SQLite will run faster if it is free to make large memory allocations, 1673 ** but some application might prefer to run slower in exchange for 1674 ** guarantees about memory fragmentation that are possible if large 1675 ** allocations are avoided. This hint is normally off. 1676 ** </dd> 1677 ** 1678 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1679 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1680 ** interpreted as a boolean, which enables or disables the collection of 1681 ** memory allocation statistics. ^(When memory allocation statistics are 1682 ** disabled, the following SQLite interfaces become non-operational: 1683 ** <ul> 1684 ** <li> [sqlite3_memory_used()] 1685 ** <li> [sqlite3_memory_highwater()] 1686 ** <li> [sqlite3_soft_heap_limit64()] 1687 ** <li> [sqlite3_status64()] 1688 ** </ul>)^ 1689 ** ^Memory allocation statistics are enabled by default unless SQLite is 1690 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1691 ** allocation statistics are disabled by default. 1692 ** </dd> 1693 ** 1694 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1695 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1696 ** </dd> 1697 ** 1698 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1699 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1700 ** that SQLite can use for the database page cache with the default page 1701 ** cache implementation. 1702 ** This configuration option is a no-op if an application-define page 1703 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1704 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1705 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1706 ** and the number of cache lines (N). 1707 ** The sz argument should be the size of the largest database page 1708 ** (a power of two between 512 and 65536) plus some extra bytes for each 1709 ** page header. ^The number of extra bytes needed by the page header 1710 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1711 ** ^It is harmless, apart from the wasted memory, 1712 ** for the sz parameter to be larger than necessary. The pMem 1713 ** argument must be either a NULL pointer or a pointer to an 8-byte 1714 ** aligned block of memory of at least sz*N bytes, otherwise 1715 ** subsequent behavior is undefined. 1716 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1717 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1718 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1719 ** is exhausted. 1720 ** ^If pMem is NULL and N is non-zero, then each database connection 1721 ** does an initial bulk allocation for page cache memory 1722 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1723 ** of -1024*N bytes if N is negative, . ^If additional 1724 ** page cache memory is needed beyond what is provided by the initial 1725 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1726 ** additional cache line. </dd> 1727 ** 1728 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1729 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1730 ** that SQLite will use for all of its dynamic memory allocation needs 1731 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1732 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1733 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1734 ** [SQLITE_ERROR] if invoked otherwise. 1735 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1736 ** An 8-byte aligned pointer to the memory, 1737 ** the number of bytes in the memory buffer, and the minimum allocation size. 1738 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1739 ** to using its default memory allocator (the system malloc() implementation), 1740 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1741 ** memory pointer is not NULL then the alternative memory 1742 ** allocator is engaged to handle all of SQLites memory allocation needs. 1743 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1744 ** boundary or subsequent behavior of SQLite will be undefined. 1745 ** The minimum allocation size is capped at 2**12. Reasonable values 1746 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1747 ** 1748 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1749 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1750 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1751 ** The argument specifies alternative low-level mutex routines to be used 1752 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1753 ** the content of the [sqlite3_mutex_methods] structure before the call to 1754 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1755 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1756 ** the entire mutexing subsystem is omitted from the build and hence calls to 1757 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1758 ** return [SQLITE_ERROR].</dd> 1759 ** 1760 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1761 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1762 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1763 ** [sqlite3_mutex_methods] 1764 ** structure is filled with the currently defined mutex routines.)^ 1765 ** This option can be used to overload the default mutex allocation 1766 ** routines with a wrapper used to track mutex usage for performance 1767 ** profiling or testing, for example. ^If SQLite is compiled with 1768 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1769 ** the entire mutexing subsystem is omitted from the build and hence calls to 1770 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1771 ** return [SQLITE_ERROR].</dd> 1772 ** 1773 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1774 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1775 ** the default size of lookaside memory on each [database connection]. 1776 ** The first argument is the 1777 ** size of each lookaside buffer slot and the second is the number of 1778 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1779 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1780 ** option to [sqlite3_db_config()] can be used to change the lookaside 1781 ** configuration on individual connections.)^ </dd> 1782 ** 1783 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1784 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1785 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1786 ** the interface to a custom page cache implementation.)^ 1787 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1788 ** 1789 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1790 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1791 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1792 ** the current page cache implementation into that object.)^ </dd> 1793 ** 1794 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1795 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1796 ** global [error log]. 1797 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1798 ** function with a call signature of void(*)(void*,int,const char*), 1799 ** and a pointer to void. ^If the function pointer is not NULL, it is 1800 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1801 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1802 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1803 ** passed through as the first parameter to the application-defined logger 1804 ** function whenever that function is invoked. ^The second parameter to 1805 ** the logger function is a copy of the first parameter to the corresponding 1806 ** [sqlite3_log()] call and is intended to be a [result code] or an 1807 ** [extended result code]. ^The third parameter passed to the logger is 1808 ** log message after formatting via [sqlite3_snprintf()]. 1809 ** The SQLite logging interface is not reentrant; the logger function 1810 ** supplied by the application must not invoke any SQLite interface. 1811 ** In a multi-threaded application, the application-defined logger 1812 ** function must be threadsafe. </dd> 1813 ** 1814 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1815 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1816 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1817 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1818 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1819 ** [sqlite3_open16()] or 1820 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1821 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1822 ** connection is opened. ^If it is globally disabled, filenames are 1823 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1824 ** database connection is opened. ^(By default, URI handling is globally 1825 ** disabled. The default value may be changed by compiling with the 1826 ** [SQLITE_USE_URI] symbol defined.)^ 1827 ** 1828 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1829 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1830 ** argument which is interpreted as a boolean in order to enable or disable 1831 ** the use of covering indices for full table scans in the query optimizer. 1832 ** ^The default setting is determined 1833 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1834 ** if that compile-time option is omitted. 1835 ** The ability to disable the use of covering indices for full table scans 1836 ** is because some incorrectly coded legacy applications might malfunction 1837 ** when the optimization is enabled. Providing the ability to 1838 ** disable the optimization allows the older, buggy application code to work 1839 ** without change even with newer versions of SQLite. 1840 ** 1841 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1842 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1843 ** <dd> These options are obsolete and should not be used by new code. 1844 ** They are retained for backwards compatibility but are now no-ops. 1845 ** </dd> 1846 ** 1847 ** [[SQLITE_CONFIG_SQLLOG]] 1848 ** <dt>SQLITE_CONFIG_SQLLOG 1849 ** <dd>This option is only available if sqlite is compiled with the 1850 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1851 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1852 ** The second should be of type (void*). The callback is invoked by the library 1853 ** in three separate circumstances, identified by the value passed as the 1854 ** fourth parameter. If the fourth parameter is 0, then the database connection 1855 ** passed as the second argument has just been opened. The third argument 1856 ** points to a buffer containing the name of the main database file. If the 1857 ** fourth parameter is 1, then the SQL statement that the third parameter 1858 ** points to has just been executed. Or, if the fourth parameter is 2, then 1859 ** the connection being passed as the second parameter is being closed. The 1860 ** third parameter is passed NULL In this case. An example of using this 1861 ** configuration option can be seen in the "test_sqllog.c" source file in 1862 ** the canonical SQLite source tree.</dd> 1863 ** 1864 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1865 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1866 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1867 ** that are the default mmap size limit (the default setting for 1868 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1869 ** ^The default setting can be overridden by each database connection using 1870 ** either the [PRAGMA mmap_size] command, or by using the 1871 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1872 ** will be silently truncated if necessary so that it does not exceed the 1873 ** compile-time maximum mmap size set by the 1874 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1875 ** ^If either argument to this option is negative, then that argument is 1876 ** changed to its compile-time default. 1877 ** 1878 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1879 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1880 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1881 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1882 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1883 ** that specifies the maximum size of the created heap. 1884 ** 1885 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1886 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1887 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1888 ** is a pointer to an integer and writes into that integer the number of extra 1889 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1890 ** The amount of extra space required can change depending on the compiler, 1891 ** target platform, and SQLite version. 1892 ** 1893 ** [[SQLITE_CONFIG_PMASZ]] 1894 ** <dt>SQLITE_CONFIG_PMASZ 1895 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1896 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1897 ** sorter to that integer. The default minimum PMA Size is set by the 1898 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1899 ** to help with sort operations when multithreaded sorting 1900 ** is enabled (using the [PRAGMA threads] command) and the amount of content 1901 ** to be sorted exceeds the page size times the minimum of the 1902 ** [PRAGMA cache_size] setting and this value. 1903 ** 1904 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1905 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1906 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1907 ** becomes the [statement journal] spill-to-disk threshold. 1908 ** [Statement journals] are held in memory until their size (in bytes) 1909 ** exceeds this threshold, at which point they are written to disk. 1910 ** Or if the threshold is -1, statement journals are always held 1911 ** exclusively in memory. 1912 ** Since many statement journals never become large, setting the spill 1913 ** threshold to a value such as 64KiB can greatly reduce the amount of 1914 ** I/O required to support statement rollback. 1915 ** The default value for this setting is controlled by the 1916 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 1917 ** </dl> 1918 */ 1919 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1920 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1921 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1922 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1923 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1924 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 1925 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1926 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1927 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1928 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1929 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1930 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1931 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1932 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1933 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1934 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1935 #define SQLITE_CONFIG_URI 17 /* int */ 1936 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1937 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1938 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1939 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1940 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1941 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1942 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1943 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1944 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 1945 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 1946 1947 /* 1948 ** CAPI3REF: Database Connection Configuration Options 1949 ** 1950 ** These constants are the available integer configuration options that 1951 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 1952 ** 1953 ** New configuration options may be added in future releases of SQLite. 1954 ** Existing configuration options might be discontinued. Applications 1955 ** should check the return code from [sqlite3_db_config()] to make sure that 1956 ** the call worked. ^The [sqlite3_db_config()] interface will return a 1957 ** non-zero [error code] if a discontinued or unsupported configuration option 1958 ** is invoked. 1959 ** 1960 ** <dl> 1961 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1962 ** <dd> ^This option takes three additional arguments that determine the 1963 ** [lookaside memory allocator] configuration for the [database connection]. 1964 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1965 ** pointer to a memory buffer to use for lookaside memory. 1966 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1967 ** may be NULL in which case SQLite will allocate the 1968 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1969 ** size of each lookaside buffer slot. ^The third argument is the number of 1970 ** slots. The size of the buffer in the first argument must be greater than 1971 ** or equal to the product of the second and third arguments. The buffer 1972 ** must be aligned to an 8-byte boundary. ^If the second argument to 1973 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1974 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1975 ** configuration for a database connection can only be changed when that 1976 ** connection is not currently using lookaside memory, or in other words 1977 ** when the "current value" returned by 1978 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1979 ** Any attempt to change the lookaside memory configuration when lookaside 1980 ** memory is in use leaves the configuration unchanged and returns 1981 ** [SQLITE_BUSY].)^</dd> 1982 ** 1983 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1984 ** <dd> ^This option is used to enable or disable the enforcement of 1985 ** [foreign key constraints]. There should be two additional arguments. 1986 ** The first argument is an integer which is 0 to disable FK enforcement, 1987 ** positive to enable FK enforcement or negative to leave FK enforcement 1988 ** unchanged. The second parameter is a pointer to an integer into which 1989 ** is written 0 or 1 to indicate whether FK enforcement is off or on 1990 ** following this call. The second parameter may be a NULL pointer, in 1991 ** which case the FK enforcement setting is not reported back. </dd> 1992 ** 1993 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1994 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1995 ** There should be two additional arguments. 1996 ** The first argument is an integer which is 0 to disable triggers, 1997 ** positive to enable triggers or negative to leave the setting unchanged. 1998 ** The second parameter is a pointer to an integer into which 1999 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2000 ** following this call. The second parameter may be a NULL pointer, in 2001 ** which case the trigger setting is not reported back. </dd> 2002 ** 2003 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2004 ** <dd> ^This option is used to enable or disable the two-argument 2005 ** version of the [fts3_tokenizer()] function which is part of the 2006 ** [FTS3] full-text search engine extension. 2007 ** There should be two additional arguments. 2008 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2009 ** positive to enable fts3_tokenizer() or negative to leave the setting 2010 ** unchanged. 2011 ** The second parameter is a pointer to an integer into which 2012 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2013 ** following this call. The second parameter may be a NULL pointer, in 2014 ** which case the new setting is not reported back. </dd> 2015 ** 2016 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2017 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2018 ** interface independently of the [load_extension()] SQL function. 2019 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2020 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2021 ** There should be two additional arguments. 2022 ** When the first argument to this interface is 1, then only the C-API is 2023 ** enabled and the SQL function remains disabled. If the first argument to 2024 ** this interface is 0, then both the C-API and the SQL function are disabled. 2025 ** If the first argument is -1, then no changes are made to state of either the 2026 ** C-API or the SQL function. 2027 ** The second parameter is a pointer to an integer into which 2028 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2029 ** is disabled or enabled following this call. The second parameter may 2030 ** be a NULL pointer, in which case the new setting is not reported back. 2031 ** </dd> 2032 ** 2033 ** <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2034 ** <dd> ^This option is used to change the name of the "main" database 2035 ** schema. ^The sole argument is a pointer to a constant UTF8 string 2036 ** which will become the new schema name in place of "main". ^SQLite 2037 ** does not make a copy of the new main schema name string, so the application 2038 ** must ensure that the argument passed into this DBCONFIG option is unchanged 2039 ** until after the database connection closes. 2040 ** </dd> 2041 ** 2042 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2043 ** <dd> Usually, when a database in wal mode is closed or detached from a 2044 ** database handle, SQLite checks if this will mean that there are now no 2045 ** connections at all to the database. If so, it performs a checkpoint 2046 ** operation before closing the connection. This option may be used to 2047 ** override this behaviour. The first parameter passed to this operation 2048 ** is an integer - non-zero to disable checkpoints-on-close, or zero (the 2049 ** default) to enable them. The second parameter is a pointer to an integer 2050 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2051 ** have been disabled - 0 if they are not disabled, 1 if they are. 2052 ** </dd> 2053 ** 2054 ** <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2055 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2056 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2057 ** a single SQL query statement will always use the same algorithm regardless 2058 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2059 ** that look at the values of bound parameters, which can make some queries 2060 ** slower. But the QPSG has the advantage of more predictable behavior. With 2061 ** the QPSG active, SQLite will always use the same query plan in the field as 2062 ** was used during testing in the lab. 2063 ** </dd> 2064 ** 2065 ** </dl> 2066 */ 2067 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2068 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2069 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2070 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2071 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2072 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2073 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2074 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2075 2076 2077 /* 2078 ** CAPI3REF: Enable Or Disable Extended Result Codes 2079 ** METHOD: sqlite3 2080 ** 2081 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2082 ** [extended result codes] feature of SQLite. ^The extended result 2083 ** codes are disabled by default for historical compatibility. 2084 */ 2085 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2086 2087 /* 2088 ** CAPI3REF: Last Insert Rowid 2089 ** METHOD: sqlite3 2090 ** 2091 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2092 ** has a unique 64-bit signed 2093 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2094 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2095 ** names are not also used by explicitly declared columns. ^If 2096 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2097 ** is another alias for the rowid. 2098 ** 2099 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2100 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2101 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2102 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2103 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2104 ** zero. 2105 ** 2106 ** As well as being set automatically as rows are inserted into database 2107 ** tables, the value returned by this function may be set explicitly by 2108 ** [sqlite3_set_last_insert_rowid()] 2109 ** 2110 ** Some virtual table implementations may INSERT rows into rowid tables as 2111 ** part of committing a transaction (e.g. to flush data accumulated in memory 2112 ** to disk). In this case subsequent calls to this function return the rowid 2113 ** associated with these internal INSERT operations, which leads to 2114 ** unintuitive results. Virtual table implementations that do write to rowid 2115 ** tables in this way can avoid this problem by restoring the original 2116 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2117 ** control to the user. 2118 ** 2119 ** ^(If an [INSERT] occurs within a trigger then this routine will 2120 ** return the [rowid] of the inserted row as long as the trigger is 2121 ** running. Once the trigger program ends, the value returned 2122 ** by this routine reverts to what it was before the trigger was fired.)^ 2123 ** 2124 ** ^An [INSERT] that fails due to a constraint violation is not a 2125 ** successful [INSERT] and does not change the value returned by this 2126 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2127 ** and INSERT OR ABORT make no changes to the return value of this 2128 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2129 ** encounters a constraint violation, it does not fail. The 2130 ** INSERT continues to completion after deleting rows that caused 2131 ** the constraint problem so INSERT OR REPLACE will always change 2132 ** the return value of this interface.)^ 2133 ** 2134 ** ^For the purposes of this routine, an [INSERT] is considered to 2135 ** be successful even if it is subsequently rolled back. 2136 ** 2137 ** This function is accessible to SQL statements via the 2138 ** [last_insert_rowid() SQL function]. 2139 ** 2140 ** If a separate thread performs a new [INSERT] on the same 2141 ** database connection while the [sqlite3_last_insert_rowid()] 2142 ** function is running and thus changes the last insert [rowid], 2143 ** then the value returned by [sqlite3_last_insert_rowid()] is 2144 ** unpredictable and might not equal either the old or the new 2145 ** last insert [rowid]. 2146 */ 2147 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2148 2149 /* 2150 ** CAPI3REF: Set the Last Insert Rowid value. 2151 ** METHOD: sqlite3 2152 ** 2153 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2154 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2155 ** without inserting a row into the database. 2156 */ 2157 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2158 2159 /* 2160 ** CAPI3REF: Count The Number Of Rows Modified 2161 ** METHOD: sqlite3 2162 ** 2163 ** ^This function returns the number of rows modified, inserted or 2164 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2165 ** statement on the database connection specified by the only parameter. 2166 ** ^Executing any other type of SQL statement does not modify the value 2167 ** returned by this function. 2168 ** 2169 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2170 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2171 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2172 ** 2173 ** Changes to a view that are intercepted by 2174 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2175 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2176 ** DELETE statement run on a view is always zero. Only changes made to real 2177 ** tables are counted. 2178 ** 2179 ** Things are more complicated if the sqlite3_changes() function is 2180 ** executed while a trigger program is running. This may happen if the 2181 ** program uses the [changes() SQL function], or if some other callback 2182 ** function invokes sqlite3_changes() directly. Essentially: 2183 ** 2184 ** <ul> 2185 ** <li> ^(Before entering a trigger program the value returned by 2186 ** sqlite3_changes() function is saved. After the trigger program 2187 ** has finished, the original value is restored.)^ 2188 ** 2189 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2190 ** statement sets the value returned by sqlite3_changes() 2191 ** upon completion as normal. Of course, this value will not include 2192 ** any changes performed by sub-triggers, as the sqlite3_changes() 2193 ** value will be saved and restored after each sub-trigger has run.)^ 2194 ** </ul> 2195 ** 2196 ** ^This means that if the changes() SQL function (or similar) is used 2197 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2198 ** returns the value as set when the calling statement began executing. 2199 ** ^If it is used by the second or subsequent such statement within a trigger 2200 ** program, the value returned reflects the number of rows modified by the 2201 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2202 ** 2203 ** See also the [sqlite3_total_changes()] interface, the 2204 ** [count_changes pragma], and the [changes() SQL function]. 2205 ** 2206 ** If a separate thread makes changes on the same database connection 2207 ** while [sqlite3_changes()] is running then the value returned 2208 ** is unpredictable and not meaningful. 2209 */ 2210 SQLITE_API int sqlite3_changes(sqlite3*); 2211 2212 /* 2213 ** CAPI3REF: Total Number Of Rows Modified 2214 ** METHOD: sqlite3 2215 ** 2216 ** ^This function returns the total number of rows inserted, modified or 2217 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2218 ** since the database connection was opened, including those executed as 2219 ** part of trigger programs. ^Executing any other type of SQL statement 2220 ** does not affect the value returned by sqlite3_total_changes(). 2221 ** 2222 ** ^Changes made as part of [foreign key actions] are included in the 2223 ** count, but those made as part of REPLACE constraint resolution are 2224 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2225 ** are not counted. 2226 ** 2227 ** See also the [sqlite3_changes()] interface, the 2228 ** [count_changes pragma], and the [total_changes() SQL function]. 2229 ** 2230 ** If a separate thread makes changes on the same database connection 2231 ** while [sqlite3_total_changes()] is running then the value 2232 ** returned is unpredictable and not meaningful. 2233 */ 2234 SQLITE_API int sqlite3_total_changes(sqlite3*); 2235 2236 /* 2237 ** CAPI3REF: Interrupt A Long-Running Query 2238 ** METHOD: sqlite3 2239 ** 2240 ** ^This function causes any pending database operation to abort and 2241 ** return at its earliest opportunity. This routine is typically 2242 ** called in response to a user action such as pressing "Cancel" 2243 ** or Ctrl-C where the user wants a long query operation to halt 2244 ** immediately. 2245 ** 2246 ** ^It is safe to call this routine from a thread different from the 2247 ** thread that is currently running the database operation. But it 2248 ** is not safe to call this routine with a [database connection] that 2249 ** is closed or might close before sqlite3_interrupt() returns. 2250 ** 2251 ** ^If an SQL operation is very nearly finished at the time when 2252 ** sqlite3_interrupt() is called, then it might not have an opportunity 2253 ** to be interrupted and might continue to completion. 2254 ** 2255 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2256 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2257 ** that is inside an explicit transaction, then the entire transaction 2258 ** will be rolled back automatically. 2259 ** 2260 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2261 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2262 ** that are started after the sqlite3_interrupt() call and before the 2263 ** running statements reaches zero are interrupted as if they had been 2264 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2265 ** that are started after the running statement count reaches zero are 2266 ** not effected by the sqlite3_interrupt(). 2267 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2268 ** SQL statements is a no-op and has no effect on SQL statements 2269 ** that are started after the sqlite3_interrupt() call returns. 2270 */ 2271 SQLITE_API void sqlite3_interrupt(sqlite3*); 2272 2273 /* 2274 ** CAPI3REF: Determine If An SQL Statement Is Complete 2275 ** 2276 ** These routines are useful during command-line input to determine if the 2277 ** currently entered text seems to form a complete SQL statement or 2278 ** if additional input is needed before sending the text into 2279 ** SQLite for parsing. ^These routines return 1 if the input string 2280 ** appears to be a complete SQL statement. ^A statement is judged to be 2281 ** complete if it ends with a semicolon token and is not a prefix of a 2282 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2283 ** string literals or quoted identifier names or comments are not 2284 ** independent tokens (they are part of the token in which they are 2285 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2286 ** and comments that follow the final semicolon are ignored. 2287 ** 2288 ** ^These routines return 0 if the statement is incomplete. ^If a 2289 ** memory allocation fails, then SQLITE_NOMEM is returned. 2290 ** 2291 ** ^These routines do not parse the SQL statements thus 2292 ** will not detect syntactically incorrect SQL. 2293 ** 2294 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2295 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2296 ** automatically by sqlite3_complete16(). If that initialization fails, 2297 ** then the return value from sqlite3_complete16() will be non-zero 2298 ** regardless of whether or not the input SQL is complete.)^ 2299 ** 2300 ** The input to [sqlite3_complete()] must be a zero-terminated 2301 ** UTF-8 string. 2302 ** 2303 ** The input to [sqlite3_complete16()] must be a zero-terminated 2304 ** UTF-16 string in native byte order. 2305 */ 2306 SQLITE_API int sqlite3_complete(const char *sql); 2307 SQLITE_API int sqlite3_complete16(const void *sql); 2308 2309 /* 2310 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2311 ** KEYWORDS: {busy-handler callback} {busy handler} 2312 ** METHOD: sqlite3 2313 ** 2314 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2315 ** that might be invoked with argument P whenever 2316 ** an attempt is made to access a database table associated with 2317 ** [database connection] D when another thread 2318 ** or process has the table locked. 2319 ** The sqlite3_busy_handler() interface is used to implement 2320 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2321 ** 2322 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2323 ** is returned immediately upon encountering the lock. ^If the busy callback 2324 ** is not NULL, then the callback might be invoked with two arguments. 2325 ** 2326 ** ^The first argument to the busy handler is a copy of the void* pointer which 2327 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2328 ** the busy handler callback is the number of times that the busy handler has 2329 ** been invoked previously for the same locking event. ^If the 2330 ** busy callback returns 0, then no additional attempts are made to 2331 ** access the database and [SQLITE_BUSY] is returned 2332 ** to the application. 2333 ** ^If the callback returns non-zero, then another attempt 2334 ** is made to access the database and the cycle repeats. 2335 ** 2336 ** The presence of a busy handler does not guarantee that it will be invoked 2337 ** when there is lock contention. ^If SQLite determines that invoking the busy 2338 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2339 ** to the application instead of invoking the 2340 ** busy handler. 2341 ** Consider a scenario where one process is holding a read lock that 2342 ** it is trying to promote to a reserved lock and 2343 ** a second process is holding a reserved lock that it is trying 2344 ** to promote to an exclusive lock. The first process cannot proceed 2345 ** because it is blocked by the second and the second process cannot 2346 ** proceed because it is blocked by the first. If both processes 2347 ** invoke the busy handlers, neither will make any progress. Therefore, 2348 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2349 ** will induce the first process to release its read lock and allow 2350 ** the second process to proceed. 2351 ** 2352 ** ^The default busy callback is NULL. 2353 ** 2354 ** ^(There can only be a single busy handler defined for each 2355 ** [database connection]. Setting a new busy handler clears any 2356 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2357 ** or evaluating [PRAGMA busy_timeout=N] will change the 2358 ** busy handler and thus clear any previously set busy handler. 2359 ** 2360 ** The busy callback should not take any actions which modify the 2361 ** database connection that invoked the busy handler. In other words, 2362 ** the busy handler is not reentrant. Any such actions 2363 ** result in undefined behavior. 2364 ** 2365 ** A busy handler must not close the database connection 2366 ** or [prepared statement] that invoked the busy handler. 2367 */ 2368 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2369 2370 /* 2371 ** CAPI3REF: Set A Busy Timeout 2372 ** METHOD: sqlite3 2373 ** 2374 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2375 ** for a specified amount of time when a table is locked. ^The handler 2376 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2377 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2378 ** the handler returns 0 which causes [sqlite3_step()] to return 2379 ** [SQLITE_BUSY]. 2380 ** 2381 ** ^Calling this routine with an argument less than or equal to zero 2382 ** turns off all busy handlers. 2383 ** 2384 ** ^(There can only be a single busy handler for a particular 2385 ** [database connection] at any given moment. If another busy handler 2386 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2387 ** this routine, that other busy handler is cleared.)^ 2388 ** 2389 ** See also: [PRAGMA busy_timeout] 2390 */ 2391 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2392 2393 /* 2394 ** CAPI3REF: Convenience Routines For Running Queries 2395 ** METHOD: sqlite3 2396 ** 2397 ** This is a legacy interface that is preserved for backwards compatibility. 2398 ** Use of this interface is not recommended. 2399 ** 2400 ** Definition: A <b>result table</b> is memory data structure created by the 2401 ** [sqlite3_get_table()] interface. A result table records the 2402 ** complete query results from one or more queries. 2403 ** 2404 ** The table conceptually has a number of rows and columns. But 2405 ** these numbers are not part of the result table itself. These 2406 ** numbers are obtained separately. Let N be the number of rows 2407 ** and M be the number of columns. 2408 ** 2409 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2410 ** There are (N+1)*M elements in the array. The first M pointers point 2411 ** to zero-terminated strings that contain the names of the columns. 2412 ** The remaining entries all point to query results. NULL values result 2413 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2414 ** string representation as returned by [sqlite3_column_text()]. 2415 ** 2416 ** A result table might consist of one or more memory allocations. 2417 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2418 ** A result table should be deallocated using [sqlite3_free_table()]. 2419 ** 2420 ** ^(As an example of the result table format, suppose a query result 2421 ** is as follows: 2422 ** 2423 ** <blockquote><pre> 2424 ** Name | Age 2425 ** ----------------------- 2426 ** Alice | 43 2427 ** Bob | 28 2428 ** Cindy | 21 2429 ** </pre></blockquote> 2430 ** 2431 ** There are two column (M==2) and three rows (N==3). Thus the 2432 ** result table has 8 entries. Suppose the result table is stored 2433 ** in an array names azResult. Then azResult holds this content: 2434 ** 2435 ** <blockquote><pre> 2436 ** azResult[0] = "Name"; 2437 ** azResult[1] = "Age"; 2438 ** azResult[2] = "Alice"; 2439 ** azResult[3] = "43"; 2440 ** azResult[4] = "Bob"; 2441 ** azResult[5] = "28"; 2442 ** azResult[6] = "Cindy"; 2443 ** azResult[7] = "21"; 2444 ** </pre></blockquote>)^ 2445 ** 2446 ** ^The sqlite3_get_table() function evaluates one or more 2447 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2448 ** string of its 2nd parameter and returns a result table to the 2449 ** pointer given in its 3rd parameter. 2450 ** 2451 ** After the application has finished with the result from sqlite3_get_table(), 2452 ** it must pass the result table pointer to sqlite3_free_table() in order to 2453 ** release the memory that was malloced. Because of the way the 2454 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2455 ** function must not try to call [sqlite3_free()] directly. Only 2456 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2457 ** 2458 ** The sqlite3_get_table() interface is implemented as a wrapper around 2459 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2460 ** to any internal data structures of SQLite. It uses only the public 2461 ** interface defined here. As a consequence, errors that occur in the 2462 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2463 ** reflected in subsequent calls to [sqlite3_errcode()] or 2464 ** [sqlite3_errmsg()]. 2465 */ 2466 SQLITE_API int sqlite3_get_table( 2467 sqlite3 *db, /* An open database */ 2468 const char *zSql, /* SQL to be evaluated */ 2469 char ***pazResult, /* Results of the query */ 2470 int *pnRow, /* Number of result rows written here */ 2471 int *pnColumn, /* Number of result columns written here */ 2472 char **pzErrmsg /* Error msg written here */ 2473 ); 2474 SQLITE_API void sqlite3_free_table(char **result); 2475 2476 /* 2477 ** CAPI3REF: Formatted String Printing Functions 2478 ** 2479 ** These routines are work-alikes of the "printf()" family of functions 2480 ** from the standard C library. 2481 ** These routines understand most of the common K&R formatting options, 2482 ** plus some additional non-standard formats, detailed below. 2483 ** Note that some of the more obscure formatting options from recent 2484 ** C-library standards are omitted from this implementation. 2485 ** 2486 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2487 ** results into memory obtained from [sqlite3_malloc()]. 2488 ** The strings returned by these two routines should be 2489 ** released by [sqlite3_free()]. ^Both routines return a 2490 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2491 ** memory to hold the resulting string. 2492 ** 2493 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2494 ** the standard C library. The result is written into the 2495 ** buffer supplied as the second parameter whose size is given by 2496 ** the first parameter. Note that the order of the 2497 ** first two parameters is reversed from snprintf().)^ This is an 2498 ** historical accident that cannot be fixed without breaking 2499 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2500 ** returns a pointer to its buffer instead of the number of 2501 ** characters actually written into the buffer.)^ We admit that 2502 ** the number of characters written would be a more useful return 2503 ** value but we cannot change the implementation of sqlite3_snprintf() 2504 ** now without breaking compatibility. 2505 ** 2506 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2507 ** guarantees that the buffer is always zero-terminated. ^The first 2508 ** parameter "n" is the total size of the buffer, including space for 2509 ** the zero terminator. So the longest string that can be completely 2510 ** written will be n-1 characters. 2511 ** 2512 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2513 ** 2514 ** These routines all implement some additional formatting 2515 ** options that are useful for constructing SQL statements. 2516 ** All of the usual printf() formatting options apply. In addition, there 2517 ** is are "%q", "%Q", "%w" and "%z" options. 2518 ** 2519 ** ^(The %q option works like %s in that it substitutes a nul-terminated 2520 ** string from the argument list. But %q also doubles every '\'' character. 2521 ** %q is designed for use inside a string literal.)^ By doubling each '\'' 2522 ** character it escapes that character and allows it to be inserted into 2523 ** the string. 2524 ** 2525 ** For example, assume the string variable zText contains text as follows: 2526 ** 2527 ** <blockquote><pre> 2528 ** char *zText = "It's a happy day!"; 2529 ** </pre></blockquote> 2530 ** 2531 ** One can use this text in an SQL statement as follows: 2532 ** 2533 ** <blockquote><pre> 2534 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2535 ** sqlite3_exec(db, zSQL, 0, 0, 0); 2536 ** sqlite3_free(zSQL); 2537 ** </pre></blockquote> 2538 ** 2539 ** Because the %q format string is used, the '\'' character in zText 2540 ** is escaped and the SQL generated is as follows: 2541 ** 2542 ** <blockquote><pre> 2543 ** INSERT INTO table1 VALUES('It''s a happy day!') 2544 ** </pre></blockquote> 2545 ** 2546 ** This is correct. Had we used %s instead of %q, the generated SQL 2547 ** would have looked like this: 2548 ** 2549 ** <blockquote><pre> 2550 ** INSERT INTO table1 VALUES('It's a happy day!'); 2551 ** </pre></blockquote> 2552 ** 2553 ** This second example is an SQL syntax error. As a general rule you should 2554 ** always use %q instead of %s when inserting text into a string literal. 2555 ** 2556 ** ^(The %Q option works like %q except it also adds single quotes around 2557 ** the outside of the total string. Additionally, if the parameter in the 2558 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2559 ** single quotes).)^ So, for example, one could say: 2560 ** 2561 ** <blockquote><pre> 2562 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2563 ** sqlite3_exec(db, zSQL, 0, 0, 0); 2564 ** sqlite3_free(zSQL); 2565 ** </pre></blockquote> 2566 ** 2567 ** The code above will render a correct SQL statement in the zSQL 2568 ** variable even if the zText variable is a NULL pointer. 2569 ** 2570 ** ^(The "%w" formatting option is like "%q" except that it expects to 2571 ** be contained within double-quotes instead of single quotes, and it 2572 ** escapes the double-quote character instead of the single-quote 2573 ** character.)^ The "%w" formatting option is intended for safely inserting 2574 ** table and column names into a constructed SQL statement. 2575 ** 2576 ** ^(The "%z" formatting option works like "%s" but with the 2577 ** addition that after the string has been read and copied into 2578 ** the result, [sqlite3_free()] is called on the input string.)^ 2579 */ 2580 SQLITE_API char *sqlite3_mprintf(const char*,...); 2581 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2582 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2583 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2584 2585 /* 2586 ** CAPI3REF: Memory Allocation Subsystem 2587 ** 2588 ** The SQLite core uses these three routines for all of its own 2589 ** internal memory allocation needs. "Core" in the previous sentence 2590 ** does not include operating-system specific VFS implementation. The 2591 ** Windows VFS uses native malloc() and free() for some operations. 2592 ** 2593 ** ^The sqlite3_malloc() routine returns a pointer to a block 2594 ** of memory at least N bytes in length, where N is the parameter. 2595 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2596 ** memory, it returns a NULL pointer. ^If the parameter N to 2597 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2598 ** a NULL pointer. 2599 ** 2600 ** ^The sqlite3_malloc64(N) routine works just like 2601 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2602 ** of a signed 32-bit integer. 2603 ** 2604 ** ^Calling sqlite3_free() with a pointer previously returned 2605 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2606 ** that it might be reused. ^The sqlite3_free() routine is 2607 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2608 ** to sqlite3_free() is harmless. After being freed, memory 2609 ** should neither be read nor written. Even reading previously freed 2610 ** memory might result in a segmentation fault or other severe error. 2611 ** Memory corruption, a segmentation fault, or other severe error 2612 ** might result if sqlite3_free() is called with a non-NULL pointer that 2613 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2614 ** 2615 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2616 ** prior memory allocation X to be at least N bytes. 2617 ** ^If the X parameter to sqlite3_realloc(X,N) 2618 ** is a NULL pointer then its behavior is identical to calling 2619 ** sqlite3_malloc(N). 2620 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2621 ** negative then the behavior is exactly the same as calling 2622 ** sqlite3_free(X). 2623 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2624 ** of at least N bytes in size or NULL if insufficient memory is available. 2625 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2626 ** of the prior allocation are copied into the beginning of buffer returned 2627 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2628 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2629 ** prior allocation is not freed. 2630 ** 2631 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2632 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2633 ** of a 32-bit signed integer. 2634 ** 2635 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2636 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2637 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2638 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2639 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2640 ** sqlite3_msize(X) returns zero. If X points to something that is not 2641 ** the beginning of memory allocation, or if it points to a formerly 2642 ** valid memory allocation that has now been freed, then the behavior 2643 ** of sqlite3_msize(X) is undefined and possibly harmful. 2644 ** 2645 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2646 ** sqlite3_malloc64(), and sqlite3_realloc64() 2647 ** is always aligned to at least an 8 byte boundary, or to a 2648 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2649 ** option is used. 2650 ** 2651 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2652 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2653 ** implementation of these routines to be omitted. That capability 2654 ** is no longer provided. Only built-in memory allocators can be used. 2655 ** 2656 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2657 ** the system malloc() and free() directly when converting 2658 ** filenames between the UTF-8 encoding used by SQLite 2659 ** and whatever filename encoding is used by the particular Windows 2660 ** installation. Memory allocation errors were detected, but 2661 ** they were reported back as [SQLITE_CANTOPEN] or 2662 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2663 ** 2664 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2665 ** must be either NULL or else pointers obtained from a prior 2666 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2667 ** not yet been released. 2668 ** 2669 ** The application must not read or write any part of 2670 ** a block of memory after it has been released using 2671 ** [sqlite3_free()] or [sqlite3_realloc()]. 2672 */ 2673 SQLITE_API void *sqlite3_malloc(int); 2674 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2675 SQLITE_API void *sqlite3_realloc(void*, int); 2676 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2677 SQLITE_API void sqlite3_free(void*); 2678 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2679 2680 /* 2681 ** CAPI3REF: Memory Allocator Statistics 2682 ** 2683 ** SQLite provides these two interfaces for reporting on the status 2684 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2685 ** routines, which form the built-in memory allocation subsystem. 2686 ** 2687 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2688 ** of memory currently outstanding (malloced but not freed). 2689 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2690 ** value of [sqlite3_memory_used()] since the high-water mark 2691 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2692 ** [sqlite3_memory_highwater()] include any overhead 2693 ** added by SQLite in its implementation of [sqlite3_malloc()], 2694 ** but not overhead added by the any underlying system library 2695 ** routines that [sqlite3_malloc()] may call. 2696 ** 2697 ** ^The memory high-water mark is reset to the current value of 2698 ** [sqlite3_memory_used()] if and only if the parameter to 2699 ** [sqlite3_memory_highwater()] is true. ^The value returned 2700 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2701 ** prior to the reset. 2702 */ 2703 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2704 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2705 2706 /* 2707 ** CAPI3REF: Pseudo-Random Number Generator 2708 ** 2709 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2710 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2711 ** already uses the largest possible [ROWID]. The PRNG is also used for 2712 ** the build-in random() and randomblob() SQL functions. This interface allows 2713 ** applications to access the same PRNG for other purposes. 2714 ** 2715 ** ^A call to this routine stores N bytes of randomness into buffer P. 2716 ** ^The P parameter can be a NULL pointer. 2717 ** 2718 ** ^If this routine has not been previously called or if the previous 2719 ** call had N less than one or a NULL pointer for P, then the PRNG is 2720 ** seeded using randomness obtained from the xRandomness method of 2721 ** the default [sqlite3_vfs] object. 2722 ** ^If the previous call to this routine had an N of 1 or more and a 2723 ** non-NULL P then the pseudo-randomness is generated 2724 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2725 ** method. 2726 */ 2727 SQLITE_API void sqlite3_randomness(int N, void *P); 2728 2729 /* 2730 ** CAPI3REF: Compile-Time Authorization Callbacks 2731 ** METHOD: sqlite3 2732 ** KEYWORDS: {authorizer callback} 2733 ** 2734 ** ^This routine registers an authorizer callback with a particular 2735 ** [database connection], supplied in the first argument. 2736 ** ^The authorizer callback is invoked as SQL statements are being compiled 2737 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2738 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2739 ** and [sqlite3_prepare16_v3()]. ^At various 2740 ** points during the compilation process, as logic is being created 2741 ** to perform various actions, the authorizer callback is invoked to 2742 ** see if those actions are allowed. ^The authorizer callback should 2743 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2744 ** specific action but allow the SQL statement to continue to be 2745 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2746 ** rejected with an error. ^If the authorizer callback returns 2747 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2748 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2749 ** the authorizer will fail with an error message. 2750 ** 2751 ** When the callback returns [SQLITE_OK], that means the operation 2752 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2753 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2754 ** authorizer will fail with an error message explaining that 2755 ** access is denied. 2756 ** 2757 ** ^The first parameter to the authorizer callback is a copy of the third 2758 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2759 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2760 ** the particular action to be authorized. ^The third through sixth parameters 2761 ** to the callback are either NULL pointers or zero-terminated strings 2762 ** that contain additional details about the action to be authorized. 2763 ** Applications must always be prepared to encounter a NULL pointer in any 2764 ** of the third through the sixth parameters of the authorization callback. 2765 ** 2766 ** ^If the action code is [SQLITE_READ] 2767 ** and the callback returns [SQLITE_IGNORE] then the 2768 ** [prepared statement] statement is constructed to substitute 2769 ** a NULL value in place of the table column that would have 2770 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2771 ** return can be used to deny an untrusted user access to individual 2772 ** columns of a table. 2773 ** ^When a table is referenced by a [SELECT] but no column values are 2774 ** extracted from that table (for example in a query like 2775 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2776 ** is invoked once for that table with a column name that is an empty string. 2777 ** ^If the action code is [SQLITE_DELETE] and the callback returns 2778 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2779 ** [truncate optimization] is disabled and all rows are deleted individually. 2780 ** 2781 ** An authorizer is used when [sqlite3_prepare | preparing] 2782 ** SQL statements from an untrusted source, to ensure that the SQL statements 2783 ** do not try to access data they are not allowed to see, or that they do not 2784 ** try to execute malicious statements that damage the database. For 2785 ** example, an application may allow a user to enter arbitrary 2786 ** SQL queries for evaluation by a database. But the application does 2787 ** not want the user to be able to make arbitrary changes to the 2788 ** database. An authorizer could then be put in place while the 2789 ** user-entered SQL is being [sqlite3_prepare | prepared] that 2790 ** disallows everything except [SELECT] statements. 2791 ** 2792 ** Applications that need to process SQL from untrusted sources 2793 ** might also consider lowering resource limits using [sqlite3_limit()] 2794 ** and limiting database size using the [max_page_count] [PRAGMA] 2795 ** in addition to using an authorizer. 2796 ** 2797 ** ^(Only a single authorizer can be in place on a database connection 2798 ** at a time. Each call to sqlite3_set_authorizer overrides the 2799 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2800 ** The authorizer is disabled by default. 2801 ** 2802 ** The authorizer callback must not do anything that will modify 2803 ** the database connection that invoked the authorizer callback. 2804 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2805 ** database connections for the meaning of "modify" in this paragraph. 2806 ** 2807 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2808 ** statement might be re-prepared during [sqlite3_step()] due to a 2809 ** schema change. Hence, the application should ensure that the 2810 ** correct authorizer callback remains in place during the [sqlite3_step()]. 2811 ** 2812 ** ^Note that the authorizer callback is invoked only during 2813 ** [sqlite3_prepare()] or its variants. Authorization is not 2814 ** performed during statement evaluation in [sqlite3_step()], unless 2815 ** as stated in the previous paragraph, sqlite3_step() invokes 2816 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2817 */ 2818 SQLITE_API int sqlite3_set_authorizer( 2819 sqlite3*, 2820 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2821 void *pUserData 2822 ); 2823 2824 /* 2825 ** CAPI3REF: Authorizer Return Codes 2826 ** 2827 ** The [sqlite3_set_authorizer | authorizer callback function] must 2828 ** return either [SQLITE_OK] or one of these two constants in order 2829 ** to signal SQLite whether or not the action is permitted. See the 2830 ** [sqlite3_set_authorizer | authorizer documentation] for additional 2831 ** information. 2832 ** 2833 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2834 ** returned from the [sqlite3_vtab_on_conflict()] interface. 2835 */ 2836 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2837 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2838 2839 /* 2840 ** CAPI3REF: Authorizer Action Codes 2841 ** 2842 ** The [sqlite3_set_authorizer()] interface registers a callback function 2843 ** that is invoked to authorize certain SQL statement actions. The 2844 ** second parameter to the callback is an integer code that specifies 2845 ** what action is being authorized. These are the integer action codes that 2846 ** the authorizer callback may be passed. 2847 ** 2848 ** These action code values signify what kind of operation is to be 2849 ** authorized. The 3rd and 4th parameters to the authorization 2850 ** callback function will be parameters or NULL depending on which of these 2851 ** codes is used as the second parameter. ^(The 5th parameter to the 2852 ** authorizer callback is the name of the database ("main", "temp", 2853 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2854 ** is the name of the inner-most trigger or view that is responsible for 2855 ** the access attempt or NULL if this access attempt is directly from 2856 ** top-level SQL code. 2857 */ 2858 /******************************************* 3rd ************ 4th ***********/ 2859 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2860 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2861 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2862 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2863 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2864 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2865 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2866 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2867 #define SQLITE_DELETE 9 /* Table Name NULL */ 2868 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2869 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2870 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2871 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2872 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2873 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2874 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2875 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2876 #define SQLITE_INSERT 18 /* Table Name NULL */ 2877 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2878 #define SQLITE_READ 20 /* Table Name Column Name */ 2879 #define SQLITE_SELECT 21 /* NULL NULL */ 2880 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 2881 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 2882 #define SQLITE_ATTACH 24 /* Filename NULL */ 2883 #define SQLITE_DETACH 25 /* Database Name NULL */ 2884 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2885 #define SQLITE_REINDEX 27 /* Index Name NULL */ 2886 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 2887 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2888 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2889 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 2890 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2891 #define SQLITE_COPY 0 /* No longer used */ 2892 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 2893 2894 /* 2895 ** CAPI3REF: Tracing And Profiling Functions 2896 ** METHOD: sqlite3 2897 ** 2898 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 2899 ** instead of the routines described here. 2900 ** 2901 ** These routines register callback functions that can be used for 2902 ** tracing and profiling the execution of SQL statements. 2903 ** 2904 ** ^The callback function registered by sqlite3_trace() is invoked at 2905 ** various times when an SQL statement is being run by [sqlite3_step()]. 2906 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2907 ** SQL statement text as the statement first begins executing. 2908 ** ^(Additional sqlite3_trace() callbacks might occur 2909 ** as each triggered subprogram is entered. The callbacks for triggers 2910 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 2911 ** 2912 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2913 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2914 ** 2915 ** ^The callback function registered by sqlite3_profile() is invoked 2916 ** as each SQL statement finishes. ^The profile callback contains 2917 ** the original statement text and an estimate of wall-clock time 2918 ** of how long that statement took to run. ^The profile callback 2919 ** time is in units of nanoseconds, however the current implementation 2920 ** is only capable of millisecond resolution so the six least significant 2921 ** digits in the time are meaningless. Future versions of SQLite 2922 ** might provide greater resolution on the profiler callback. The 2923 ** sqlite3_profile() function is considered experimental and is 2924 ** subject to change in future versions of SQLite. 2925 */ 2926 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 2927 void(*xTrace)(void*,const char*), void*); 2928 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 2929 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2930 2931 /* 2932 ** CAPI3REF: SQL Trace Event Codes 2933 ** KEYWORDS: SQLITE_TRACE 2934 ** 2935 ** These constants identify classes of events that can be monitored 2936 ** using the [sqlite3_trace_v2()] tracing logic. The third argument 2937 ** to [sqlite3_trace_v2()] is an OR-ed combination of one or more of 2938 ** the following constants. ^The first argument to the trace callback 2939 ** is one of the following constants. 2940 ** 2941 ** New tracing constants may be added in future releases. 2942 ** 2943 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 2944 ** ^The T argument is one of the integer type codes above. 2945 ** ^The C argument is a copy of the context pointer passed in as the 2946 ** fourth argument to [sqlite3_trace_v2()]. 2947 ** The P and X arguments are pointers whose meanings depend on T. 2948 ** 2949 ** <dl> 2950 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 2951 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 2952 ** first begins running and possibly at other times during the 2953 ** execution of the prepared statement, such as at the start of each 2954 ** trigger subprogram. ^The P argument is a pointer to the 2955 ** [prepared statement]. ^The X argument is a pointer to a string which 2956 ** is the unexpanded SQL text of the prepared statement or an SQL comment 2957 ** that indicates the invocation of a trigger. ^The callback can compute 2958 ** the same text that would have been returned by the legacy [sqlite3_trace()] 2959 ** interface by using the X argument when X begins with "--" and invoking 2960 ** [sqlite3_expanded_sql(P)] otherwise. 2961 ** 2962 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 2963 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 2964 ** information as is provided by the [sqlite3_profile()] callback. 2965 ** ^The P argument is a pointer to the [prepared statement] and the 2966 ** X argument points to a 64-bit integer which is the estimated of 2967 ** the number of nanosecond that the prepared statement took to run. 2968 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 2969 ** 2970 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 2971 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 2972 ** statement generates a single row of result. 2973 ** ^The P argument is a pointer to the [prepared statement] and the 2974 ** X argument is unused. 2975 ** 2976 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 2977 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 2978 ** connection closes. 2979 ** ^The P argument is a pointer to the [database connection] object 2980 ** and the X argument is unused. 2981 ** </dl> 2982 */ 2983 #define SQLITE_TRACE_STMT 0x01 2984 #define SQLITE_TRACE_PROFILE 0x02 2985 #define SQLITE_TRACE_ROW 0x04 2986 #define SQLITE_TRACE_CLOSE 0x08 2987 2988 /* 2989 ** CAPI3REF: SQL Trace Hook 2990 ** METHOD: sqlite3 2991 ** 2992 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 2993 ** function X against [database connection] D, using property mask M 2994 ** and context pointer P. ^If the X callback is 2995 ** NULL or if the M mask is zero, then tracing is disabled. The 2996 ** M argument should be the bitwise OR-ed combination of 2997 ** zero or more [SQLITE_TRACE] constants. 2998 ** 2999 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3000 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3001 ** 3002 ** ^The X callback is invoked whenever any of the events identified by 3003 ** mask M occur. ^The integer return value from the callback is currently 3004 ** ignored, though this may change in future releases. Callback 3005 ** implementations should return zero to ensure future compatibility. 3006 ** 3007 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3008 ** ^The T argument is one of the [SQLITE_TRACE] 3009 ** constants to indicate why the callback was invoked. 3010 ** ^The C argument is a copy of the context pointer. 3011 ** The P and X arguments are pointers whose meanings depend on T. 3012 ** 3013 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3014 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3015 ** are deprecated. 3016 */ 3017 SQLITE_API int sqlite3_trace_v2( 3018 sqlite3*, 3019 unsigned uMask, 3020 int(*xCallback)(unsigned,void*,void*,void*), 3021 void *pCtx 3022 ); 3023 3024 /* 3025 ** CAPI3REF: Query Progress Callbacks 3026 ** METHOD: sqlite3 3027 ** 3028 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3029 ** function X to be invoked periodically during long running calls to 3030 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3031 ** database connection D. An example use for this 3032 ** interface is to keep a GUI updated during a large query. 3033 ** 3034 ** ^The parameter P is passed through as the only parameter to the 3035 ** callback function X. ^The parameter N is the approximate number of 3036 ** [virtual machine instructions] that are evaluated between successive 3037 ** invocations of the callback X. ^If N is less than one then the progress 3038 ** handler is disabled. 3039 ** 3040 ** ^Only a single progress handler may be defined at one time per 3041 ** [database connection]; setting a new progress handler cancels the 3042 ** old one. ^Setting parameter X to NULL disables the progress handler. 3043 ** ^The progress handler is also disabled by setting N to a value less 3044 ** than 1. 3045 ** 3046 ** ^If the progress callback returns non-zero, the operation is 3047 ** interrupted. This feature can be used to implement a 3048 ** "Cancel" button on a GUI progress dialog box. 3049 ** 3050 ** The progress handler callback must not do anything that will modify 3051 ** the database connection that invoked the progress handler. 3052 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3053 ** database connections for the meaning of "modify" in this paragraph. 3054 ** 3055 */ 3056 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3057 3058 /* 3059 ** CAPI3REF: Opening A New Database Connection 3060 ** CONSTRUCTOR: sqlite3 3061 ** 3062 ** ^These routines open an SQLite database file as specified by the 3063 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3064 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3065 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3066 ** returned in *ppDb, even if an error occurs. The only exception is that 3067 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3068 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3069 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3070 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3071 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3072 ** an English language description of the error following a failure of any 3073 ** of the sqlite3_open() routines. 3074 ** 3075 ** ^The default encoding will be UTF-8 for databases created using 3076 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3077 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3078 ** 3079 ** Whether or not an error occurs when it is opened, resources 3080 ** associated with the [database connection] handle should be released by 3081 ** passing it to [sqlite3_close()] when it is no longer required. 3082 ** 3083 ** The sqlite3_open_v2() interface works like sqlite3_open() 3084 ** except that it accepts two additional parameters for additional control 3085 ** over the new database connection. ^(The flags parameter to 3086 ** sqlite3_open_v2() can take one of 3087 ** the following three values, optionally combined with the 3088 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3089 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3090 ** 3091 ** <dl> 3092 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3093 ** <dd>The database is opened in read-only mode. If the database does not 3094 ** already exist, an error is returned.</dd>)^ 3095 ** 3096 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3097 ** <dd>The database is opened for reading and writing if possible, or reading 3098 ** only if the file is write protected by the operating system. In either 3099 ** case the database must already exist, otherwise an error is returned.</dd>)^ 3100 ** 3101 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3102 ** <dd>The database is opened for reading and writing, and is created if 3103 ** it does not already exist. This is the behavior that is always used for 3104 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3105 ** </dl> 3106 ** 3107 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3108 ** combinations shown above optionally combined with other 3109 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3110 ** then the behavior is undefined. 3111 ** 3112 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3113 ** opens in the multi-thread [threading mode] as long as the single-thread 3114 ** mode has not been set at compile-time or start-time. ^If the 3115 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3116 ** in the serialized [threading mode] unless single-thread was 3117 ** previously selected at compile-time or start-time. 3118 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3119 ** eligible to use [shared cache mode], regardless of whether or not shared 3120 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3121 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3122 ** participate in [shared cache mode] even if it is enabled. 3123 ** 3124 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3125 ** [sqlite3_vfs] object that defines the operating system interface that 3126 ** the new database connection should use. ^If the fourth parameter is 3127 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3128 ** 3129 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3130 ** is created for the connection. ^This in-memory database will vanish when 3131 ** the database connection is closed. Future versions of SQLite might 3132 ** make use of additional special filenames that begin with the ":" character. 3133 ** It is recommended that when a database filename actually does begin with 3134 ** a ":" character you should prefix the filename with a pathname such as 3135 ** "./" to avoid ambiguity. 3136 ** 3137 ** ^If the filename is an empty string, then a private, temporary 3138 ** on-disk database will be created. ^This private database will be 3139 ** automatically deleted as soon as the database connection is closed. 3140 ** 3141 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3142 ** 3143 ** ^If [URI filename] interpretation is enabled, and the filename argument 3144 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3145 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3146 ** set in the third argument to sqlite3_open_v2(), or if it has 3147 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3148 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3149 ** URI filename interpretation is turned off 3150 ** by default, but future releases of SQLite might enable URI filename 3151 ** interpretation by default. See "[URI filenames]" for additional 3152 ** information. 3153 ** 3154 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3155 ** authority, then it must be either an empty string or the string 3156 ** "localhost". ^If the authority is not an empty string or "localhost", an 3157 ** error is returned to the caller. ^The fragment component of a URI, if 3158 ** present, is ignored. 3159 ** 3160 ** ^SQLite uses the path component of the URI as the name of the disk file 3161 ** which contains the database. ^If the path begins with a '/' character, 3162 ** then it is interpreted as an absolute path. ^If the path does not begin 3163 ** with a '/' (meaning that the authority section is omitted from the URI) 3164 ** then the path is interpreted as a relative path. 3165 ** ^(On windows, the first component of an absolute path 3166 ** is a drive specification (e.g. "C:").)^ 3167 ** 3168 ** [[core URI query parameters]] 3169 ** The query component of a URI may contain parameters that are interpreted 3170 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3171 ** SQLite and its built-in [VFSes] interpret the 3172 ** following query parameters: 3173 ** 3174 ** <ul> 3175 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3176 ** a VFS object that provides the operating system interface that should 3177 ** be used to access the database file on disk. ^If this option is set to 3178 ** an empty string the default VFS object is used. ^Specifying an unknown 3179 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3180 ** present, then the VFS specified by the option takes precedence over 3181 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3182 ** 3183 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3184 ** "rwc", or "memory". Attempting to set it to any other value is 3185 ** an error)^. 3186 ** ^If "ro" is specified, then the database is opened for read-only 3187 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3188 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3189 ** "rw", then the database is opened for read-write (but not create) 3190 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3191 ** been set. ^Value "rwc" is equivalent to setting both 3192 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3193 ** set to "memory" then a pure [in-memory database] that never reads 3194 ** or writes from disk is used. ^It is an error to specify a value for 3195 ** the mode parameter that is less restrictive than that specified by 3196 ** the flags passed in the third parameter to sqlite3_open_v2(). 3197 ** 3198 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3199 ** "private". ^Setting it to "shared" is equivalent to setting the 3200 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3201 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3202 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3203 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3204 ** a URI filename, its value overrides any behavior requested by setting 3205 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3206 ** 3207 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3208 ** [powersafe overwrite] property does or does not apply to the 3209 ** storage media on which the database file resides. 3210 ** 3211 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3212 ** which if set disables file locking in rollback journal modes. This 3213 ** is useful for accessing a database on a filesystem that does not 3214 ** support locking. Caution: Database corruption might result if two 3215 ** or more processes write to the same database and any one of those 3216 ** processes uses nolock=1. 3217 ** 3218 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3219 ** parameter that indicates that the database file is stored on 3220 ** read-only media. ^When immutable is set, SQLite assumes that the 3221 ** database file cannot be changed, even by a process with higher 3222 ** privilege, and so the database is opened read-only and all locking 3223 ** and change detection is disabled. Caution: Setting the immutable 3224 ** property on a database file that does in fact change can result 3225 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3226 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3227 ** 3228 ** </ul> 3229 ** 3230 ** ^Specifying an unknown parameter in the query component of a URI is not an 3231 ** error. Future versions of SQLite might understand additional query 3232 ** parameters. See "[query parameters with special meaning to SQLite]" for 3233 ** additional information. 3234 ** 3235 ** [[URI filename examples]] <h3>URI filename examples</h3> 3236 ** 3237 ** <table border="1" align=center cellpadding=5> 3238 ** <tr><th> URI filenames <th> Results 3239 ** <tr><td> file:data.db <td> 3240 ** Open the file "data.db" in the current directory. 3241 ** <tr><td> file:/home/fred/data.db<br> 3242 ** file:///home/fred/data.db <br> 3243 ** file://localhost/home/fred/data.db <br> <td> 3244 ** Open the database file "/home/fred/data.db". 3245 ** <tr><td> file://darkstar/home/fred/data.db <td> 3246 ** An error. "darkstar" is not a recognized authority. 3247 ** <tr><td style="white-space:nowrap"> 3248 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3249 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3250 ** C:. Note that the %20 escaping in this example is not strictly 3251 ** necessary - space characters can be used literally 3252 ** in URI filenames. 3253 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3254 ** Open file "data.db" in the current directory for read-only access. 3255 ** Regardless of whether or not shared-cache mode is enabled by 3256 ** default, use a private cache. 3257 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3258 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3259 ** that uses dot-files in place of posix advisory locking. 3260 ** <tr><td> file:data.db?mode=readonly <td> 3261 ** An error. "readonly" is not a valid option for the "mode" parameter. 3262 ** </table> 3263 ** 3264 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3265 ** query components of a URI. A hexadecimal escape sequence consists of a 3266 ** percent sign - "%" - followed by exactly two hexadecimal digits 3267 ** specifying an octet value. ^Before the path or query components of a 3268 ** URI filename are interpreted, they are encoded using UTF-8 and all 3269 ** hexadecimal escape sequences replaced by a single byte containing the 3270 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3271 ** the results are undefined. 3272 ** 3273 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3274 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3275 ** codepage is currently defined. Filenames containing international 3276 ** characters must be converted to UTF-8 prior to passing them into 3277 ** sqlite3_open() or sqlite3_open_v2(). 3278 ** 3279 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3280 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3281 ** features that require the use of temporary files may fail. 3282 ** 3283 ** See also: [sqlite3_temp_directory] 3284 */ 3285 SQLITE_API int sqlite3_open( 3286 const char *filename, /* Database filename (UTF-8) */ 3287 sqlite3 **ppDb /* OUT: SQLite db handle */ 3288 ); 3289 SQLITE_API int sqlite3_open16( 3290 const void *filename, /* Database filename (UTF-16) */ 3291 sqlite3 **ppDb /* OUT: SQLite db handle */ 3292 ); 3293 SQLITE_API int sqlite3_open_v2( 3294 const char *filename, /* Database filename (UTF-8) */ 3295 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3296 int flags, /* Flags */ 3297 const char *zVfs /* Name of VFS module to use */ 3298 ); 3299 3300 /* 3301 ** CAPI3REF: Obtain Values For URI Parameters 3302 ** 3303 ** These are utility routines, useful to VFS implementations, that check 3304 ** to see if a database file was a URI that contained a specific query 3305 ** parameter, and if so obtains the value of that query parameter. 3306 ** 3307 ** If F is the database filename pointer passed into the xOpen() method of 3308 ** a VFS implementation when the flags parameter to xOpen() has one or 3309 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3310 ** P is the name of the query parameter, then 3311 ** sqlite3_uri_parameter(F,P) returns the value of the P 3312 ** parameter if it exists or a NULL pointer if P does not appear as a 3313 ** query parameter on F. If P is a query parameter of F 3314 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3315 ** a pointer to an empty string. 3316 ** 3317 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3318 ** parameter and returns true (1) or false (0) according to the value 3319 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3320 ** value of query parameter P is one of "yes", "true", or "on" in any 3321 ** case or if the value begins with a non-zero number. The 3322 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3323 ** query parameter P is one of "no", "false", or "off" in any case or 3324 ** if the value begins with a numeric zero. If P is not a query 3325 ** parameter on F or if the value of P is does not match any of the 3326 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3327 ** 3328 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3329 ** 64-bit signed integer and returns that integer, or D if P does not 3330 ** exist. If the value of P is something other than an integer, then 3331 ** zero is returned. 3332 ** 3333 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3334 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3335 ** is not a database file pathname pointer that SQLite passed into the xOpen 3336 ** VFS method, then the behavior of this routine is undefined and probably 3337 ** undesirable. 3338 */ 3339 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3340 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3341 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3342 3343 3344 /* 3345 ** CAPI3REF: Error Codes And Messages 3346 ** METHOD: sqlite3 3347 ** 3348 ** ^If the most recent sqlite3_* API call associated with 3349 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3350 ** returns the numeric [result code] or [extended result code] for that 3351 ** API call. 3352 ** If the most recent API call was successful, 3353 ** then the return value from sqlite3_errcode() is undefined. 3354 ** ^The sqlite3_extended_errcode() 3355 ** interface is the same except that it always returns the 3356 ** [extended result code] even when extended result codes are 3357 ** disabled. 3358 ** 3359 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3360 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3361 ** ^(Memory to hold the error message string is managed internally. 3362 ** The application does not need to worry about freeing the result. 3363 ** However, the error string might be overwritten or deallocated by 3364 ** subsequent calls to other SQLite interface functions.)^ 3365 ** 3366 ** ^The sqlite3_errstr() interface returns the English-language text 3367 ** that describes the [result code], as UTF-8. 3368 ** ^(Memory to hold the error message string is managed internally 3369 ** and must not be freed by the application)^. 3370 ** 3371 ** When the serialized [threading mode] is in use, it might be the 3372 ** case that a second error occurs on a separate thread in between 3373 ** the time of the first error and the call to these interfaces. 3374 ** When that happens, the second error will be reported since these 3375 ** interfaces always report the most recent result. To avoid 3376 ** this, each thread can obtain exclusive use of the [database connection] D 3377 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3378 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3379 ** all calls to the interfaces listed here are completed. 3380 ** 3381 ** If an interface fails with SQLITE_MISUSE, that means the interface 3382 ** was invoked incorrectly by the application. In that case, the 3383 ** error code and message may or may not be set. 3384 */ 3385 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3386 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3387 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3388 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3389 SQLITE_API const char *sqlite3_errstr(int); 3390 3391 /* 3392 ** CAPI3REF: Prepared Statement Object 3393 ** KEYWORDS: {prepared statement} {prepared statements} 3394 ** 3395 ** An instance of this object represents a single SQL statement that 3396 ** has been compiled into binary form and is ready to be evaluated. 3397 ** 3398 ** Think of each SQL statement as a separate computer program. The 3399 ** original SQL text is source code. A prepared statement object 3400 ** is the compiled object code. All SQL must be converted into a 3401 ** prepared statement before it can be run. 3402 ** 3403 ** The life-cycle of a prepared statement object usually goes like this: 3404 ** 3405 ** <ol> 3406 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3407 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3408 ** interfaces. 3409 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3410 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3411 ** to step 2. Do this zero or more times. 3412 ** <li> Destroy the object using [sqlite3_finalize()]. 3413 ** </ol> 3414 */ 3415 typedef struct sqlite3_stmt sqlite3_stmt; 3416 3417 /* 3418 ** CAPI3REF: Run-time Limits 3419 ** METHOD: sqlite3 3420 ** 3421 ** ^(This interface allows the size of various constructs to be limited 3422 ** on a connection by connection basis. The first parameter is the 3423 ** [database connection] whose limit is to be set or queried. The 3424 ** second parameter is one of the [limit categories] that define a 3425 ** class of constructs to be size limited. The third parameter is the 3426 ** new limit for that construct.)^ 3427 ** 3428 ** ^If the new limit is a negative number, the limit is unchanged. 3429 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3430 ** [limits | hard upper bound] 3431 ** set at compile-time by a C preprocessor macro called 3432 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3433 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3434 ** ^Attempts to increase a limit above its hard upper bound are 3435 ** silently truncated to the hard upper bound. 3436 ** 3437 ** ^Regardless of whether or not the limit was changed, the 3438 ** [sqlite3_limit()] interface returns the prior value of the limit. 3439 ** ^Hence, to find the current value of a limit without changing it, 3440 ** simply invoke this interface with the third parameter set to -1. 3441 ** 3442 ** Run-time limits are intended for use in applications that manage 3443 ** both their own internal database and also databases that are controlled 3444 ** by untrusted external sources. An example application might be a 3445 ** web browser that has its own databases for storing history and 3446 ** separate databases controlled by JavaScript applications downloaded 3447 ** off the Internet. The internal databases can be given the 3448 ** large, default limits. Databases managed by external sources can 3449 ** be given much smaller limits designed to prevent a denial of service 3450 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3451 ** interface to further control untrusted SQL. The size of the database 3452 ** created by an untrusted script can be contained using the 3453 ** [max_page_count] [PRAGMA]. 3454 ** 3455 ** New run-time limit categories may be added in future releases. 3456 */ 3457 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3458 3459 /* 3460 ** CAPI3REF: Run-Time Limit Categories 3461 ** KEYWORDS: {limit category} {*limit categories} 3462 ** 3463 ** These constants define various performance limits 3464 ** that can be lowered at run-time using [sqlite3_limit()]. 3465 ** The synopsis of the meanings of the various limits is shown below. 3466 ** Additional information is available at [limits | Limits in SQLite]. 3467 ** 3468 ** <dl> 3469 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3470 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3471 ** 3472 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3473 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3474 ** 3475 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3476 ** <dd>The maximum number of columns in a table definition or in the 3477 ** result set of a [SELECT] or the maximum number of columns in an index 3478 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3479 ** 3480 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3481 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3482 ** 3483 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3484 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3485 ** 3486 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3487 ** <dd>The maximum number of instructions in a virtual machine program 3488 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3489 ** the equivalent tries to allocate space for more than this many opcodes 3490 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3491 ** 3492 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3493 ** <dd>The maximum number of arguments on a function.</dd>)^ 3494 ** 3495 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3496 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3497 ** 3498 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3499 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3500 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3501 ** [GLOB] operators.</dd>)^ 3502 ** 3503 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3504 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3505 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3506 ** 3507 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3508 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3509 ** 3510 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3511 ** <dd>The maximum number of auxiliary worker threads that a single 3512 ** [prepared statement] may start.</dd>)^ 3513 ** </dl> 3514 */ 3515 #define SQLITE_LIMIT_LENGTH 0 3516 #define SQLITE_LIMIT_SQL_LENGTH 1 3517 #define SQLITE_LIMIT_COLUMN 2 3518 #define SQLITE_LIMIT_EXPR_DEPTH 3 3519 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3520 #define SQLITE_LIMIT_VDBE_OP 5 3521 #define SQLITE_LIMIT_FUNCTION_ARG 6 3522 #define SQLITE_LIMIT_ATTACHED 7 3523 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3524 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3525 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3526 #define SQLITE_LIMIT_WORKER_THREADS 11 3527 3528 /* 3529 ** CAPI3REF: Prepare Flags 3530 ** 3531 ** These constants define various flags that can be passed into 3532 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3533 ** [sqlite3_prepare16_v3()] interfaces. 3534 ** 3535 ** New flags may be added in future releases of SQLite. 3536 ** 3537 ** <dl> 3538 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3539 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3540 ** that the prepared statement will be retained for a long time and 3541 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3542 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3543 ** be used just once or at most a few times and then destroyed using 3544 ** [sqlite3_finalize()] relatively soon. The current implementation acts 3545 ** on this hint by avoiding the use of [lookaside memory] so as not to 3546 ** deplete the limited store of lookaside memory. Future versions of 3547 ** SQLite may act on this hint differently. 3548 ** </dl> 3549 */ 3550 #define SQLITE_PREPARE_PERSISTENT 0x01 3551 3552 /* 3553 ** CAPI3REF: Compiling An SQL Statement 3554 ** KEYWORDS: {SQL statement compiler} 3555 ** METHOD: sqlite3 3556 ** CONSTRUCTOR: sqlite3_stmt 3557 ** 3558 ** To execute an SQL statement, it must first be compiled into a byte-code 3559 ** program using one of these routines. Or, in other words, these routines 3560 ** are constructors for the [prepared statement] object. 3561 ** 3562 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 3563 ** [sqlite3_prepare()] interface is legacy and should be avoided. 3564 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3565 ** for special purposes. 3566 ** 3567 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 3568 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 3569 ** as a convenience. The UTF-16 interfaces work by converting the 3570 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3571 ** 3572 ** The first argument, "db", is a [database connection] obtained from a 3573 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3574 ** [sqlite3_open16()]. The database connection must not have been closed. 3575 ** 3576 ** The second argument, "zSql", is the statement to be compiled, encoded 3577 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3578 ** and sqlite3_prepare_v3() 3579 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3580 ** and sqlite3_prepare16_v3() use UTF-16. 3581 ** 3582 ** ^If the nByte argument is negative, then zSql is read up to the 3583 ** first zero terminator. ^If nByte is positive, then it is the 3584 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 3585 ** statement is generated. 3586 ** If the caller knows that the supplied string is nul-terminated, then 3587 ** there is a small performance advantage to passing an nByte parameter that 3588 ** is the number of bytes in the input string <i>including</i> 3589 ** the nul-terminator. 3590 ** 3591 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3592 ** past the end of the first SQL statement in zSql. These routines only 3593 ** compile the first statement in zSql, so *pzTail is left pointing to 3594 ** what remains uncompiled. 3595 ** 3596 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3597 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3598 ** to NULL. ^If the input text contains no SQL (if the input is an empty 3599 ** string or a comment) then *ppStmt is set to NULL. 3600 ** The calling procedure is responsible for deleting the compiled 3601 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3602 ** ppStmt may not be NULL. 3603 ** 3604 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3605 ** otherwise an [error code] is returned. 3606 ** 3607 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 3608 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 3609 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 3610 ** are retained for backwards compatibility, but their use is discouraged. 3611 ** ^In the "vX" interfaces, the prepared statement 3612 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 3613 ** original SQL text. This causes the [sqlite3_step()] interface to 3614 ** behave differently in three ways: 3615 ** 3616 ** <ol> 3617 ** <li> 3618 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3619 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 3620 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3621 ** retries will occur before sqlite3_step() gives up and returns an error. 3622 ** </li> 3623 ** 3624 ** <li> 3625 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3626 ** [error codes] or [extended error codes]. ^The legacy behavior was that 3627 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3628 ** and the application would have to make a second call to [sqlite3_reset()] 3629 ** in order to find the underlying cause of the problem. With the "v2" prepare 3630 ** interfaces, the underlying reason for the error is returned immediately. 3631 ** </li> 3632 ** 3633 ** <li> 3634 ** ^If the specific value bound to [parameter | host parameter] in the 3635 ** WHERE clause might influence the choice of query plan for a statement, 3636 ** then the statement will be automatically recompiled, as if there had been 3637 ** a schema change, on the first [sqlite3_step()] call following any change 3638 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 3639 ** ^The specific value of WHERE-clause [parameter] might influence the 3640 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 3641 ** or [GLOB] operator or if the parameter is compared to an indexed column 3642 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3643 ** </li> 3644 ** 3645 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 3646 ** the extra prepFlags parameter, which is a bit array consisting of zero or 3647 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 3648 ** sqlite3_prepare_v2() interface works exactly the same as 3649 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 3650 ** </ol> 3651 */ 3652 SQLITE_API int sqlite3_prepare( 3653 sqlite3 *db, /* Database handle */ 3654 const char *zSql, /* SQL statement, UTF-8 encoded */ 3655 int nByte, /* Maximum length of zSql in bytes. */ 3656 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3657 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3658 ); 3659 SQLITE_API int sqlite3_prepare_v2( 3660 sqlite3 *db, /* Database handle */ 3661 const char *zSql, /* SQL statement, UTF-8 encoded */ 3662 int nByte, /* Maximum length of zSql in bytes. */ 3663 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3664 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3665 ); 3666 SQLITE_API int sqlite3_prepare_v3( 3667 sqlite3 *db, /* Database handle */ 3668 const char *zSql, /* SQL statement, UTF-8 encoded */ 3669 int nByte, /* Maximum length of zSql in bytes. */ 3670 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3671 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3672 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3673 ); 3674 SQLITE_API int sqlite3_prepare16( 3675 sqlite3 *db, /* Database handle */ 3676 const void *zSql, /* SQL statement, UTF-16 encoded */ 3677 int nByte, /* Maximum length of zSql in bytes. */ 3678 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3679 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3680 ); 3681 SQLITE_API int sqlite3_prepare16_v2( 3682 sqlite3 *db, /* Database handle */ 3683 const void *zSql, /* SQL statement, UTF-16 encoded */ 3684 int nByte, /* Maximum length of zSql in bytes. */ 3685 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3686 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3687 ); 3688 SQLITE_API int sqlite3_prepare16_v3( 3689 sqlite3 *db, /* Database handle */ 3690 const void *zSql, /* SQL statement, UTF-16 encoded */ 3691 int nByte, /* Maximum length of zSql in bytes. */ 3692 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3693 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3694 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3695 ); 3696 3697 /* 3698 ** CAPI3REF: Retrieving Statement SQL 3699 ** METHOD: sqlite3_stmt 3700 ** 3701 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3702 ** SQL text used to create [prepared statement] P if P was 3703 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 3704 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 3705 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3706 ** string containing the SQL text of prepared statement P with 3707 ** [bound parameters] expanded. 3708 ** 3709 ** ^(For example, if a prepared statement is created using the SQL 3710 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3711 ** and parameter :xyz is unbound, then sqlite3_sql() will return 3712 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3713 ** will return "SELECT 2345,NULL".)^ 3714 ** 3715 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3716 ** is available to hold the result, or if the result would exceed the 3717 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3718 ** 3719 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3720 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3721 ** option causes sqlite3_expanded_sql() to always return NULL. 3722 ** 3723 ** ^The string returned by sqlite3_sql(P) is managed by SQLite and is 3724 ** automatically freed when the prepared statement is finalized. 3725 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3726 ** is obtained from [sqlite3_malloc()] and must be free by the application 3727 ** by passing it to [sqlite3_free()]. 3728 */ 3729 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 3730 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3731 3732 /* 3733 ** CAPI3REF: Determine If An SQL Statement Writes The Database 3734 ** METHOD: sqlite3_stmt 3735 ** 3736 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3737 ** and only if the [prepared statement] X makes no direct changes to 3738 ** the content of the database file. 3739 ** 3740 ** Note that [application-defined SQL functions] or 3741 ** [virtual tables] might change the database indirectly as a side effect. 3742 ** ^(For example, if an application defines a function "eval()" that 3743 ** calls [sqlite3_exec()], then the following SQL statement would 3744 ** change the database file through side-effects: 3745 ** 3746 ** <blockquote><pre> 3747 ** SELECT eval('DELETE FROM t1') FROM t2; 3748 ** </pre></blockquote> 3749 ** 3750 ** But because the [SELECT] statement does not change the database file 3751 ** directly, sqlite3_stmt_readonly() would still return true.)^ 3752 ** 3753 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3754 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3755 ** since the statements themselves do not actually modify the database but 3756 ** rather they control the timing of when other statements modify the 3757 ** database. ^The [ATTACH] and [DETACH] statements also cause 3758 ** sqlite3_stmt_readonly() to return true since, while those statements 3759 ** change the configuration of a database connection, they do not make 3760 ** changes to the content of the database files on disk. 3761 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3762 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3763 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3764 ** sqlite3_stmt_readonly() returns false for those commands. 3765 */ 3766 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3767 3768 /* 3769 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3770 ** METHOD: sqlite3_stmt 3771 ** 3772 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3773 ** [prepared statement] S has been stepped at least once using 3774 ** [sqlite3_step(S)] but has neither run to completion (returned 3775 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3776 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3777 ** interface returns false if S is a NULL pointer. If S is not a 3778 ** NULL pointer and is not a pointer to a valid [prepared statement] 3779 ** object, then the behavior is undefined and probably undesirable. 3780 ** 3781 ** This interface can be used in combination [sqlite3_next_stmt()] 3782 ** to locate all prepared statements associated with a database 3783 ** connection that are in need of being reset. This can be used, 3784 ** for example, in diagnostic routines to search for prepared 3785 ** statements that are holding a transaction open. 3786 */ 3787 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 3788 3789 /* 3790 ** CAPI3REF: Dynamically Typed Value Object 3791 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3792 ** 3793 ** SQLite uses the sqlite3_value object to represent all values 3794 ** that can be stored in a database table. SQLite uses dynamic typing 3795 ** for the values it stores. ^Values stored in sqlite3_value objects 3796 ** can be integers, floating point values, strings, BLOBs, or NULL. 3797 ** 3798 ** An sqlite3_value object may be either "protected" or "unprotected". 3799 ** Some interfaces require a protected sqlite3_value. Other interfaces 3800 ** will accept either a protected or an unprotected sqlite3_value. 3801 ** Every interface that accepts sqlite3_value arguments specifies 3802 ** whether or not it requires a protected sqlite3_value. The 3803 ** [sqlite3_value_dup()] interface can be used to construct a new 3804 ** protected sqlite3_value from an unprotected sqlite3_value. 3805 ** 3806 ** The terms "protected" and "unprotected" refer to whether or not 3807 ** a mutex is held. An internal mutex is held for a protected 3808 ** sqlite3_value object but no mutex is held for an unprotected 3809 ** sqlite3_value object. If SQLite is compiled to be single-threaded 3810 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3811 ** or if SQLite is run in one of reduced mutex modes 3812 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3813 ** then there is no distinction between protected and unprotected 3814 ** sqlite3_value objects and they can be used interchangeably. However, 3815 ** for maximum code portability it is recommended that applications 3816 ** still make the distinction between protected and unprotected 3817 ** sqlite3_value objects even when not strictly required. 3818 ** 3819 ** ^The sqlite3_value objects that are passed as parameters into the 3820 ** implementation of [application-defined SQL functions] are protected. 3821 ** ^The sqlite3_value object returned by 3822 ** [sqlite3_column_value()] is unprotected. 3823 ** Unprotected sqlite3_value objects may only be used as arguments 3824 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 3825 ** [sqlite3_value_dup()]. 3826 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 3827 ** interfaces require protected sqlite3_value objects. 3828 */ 3829 typedef struct sqlite3_value sqlite3_value; 3830 3831 /* 3832 ** CAPI3REF: SQL Function Context Object 3833 ** 3834 ** The context in which an SQL function executes is stored in an 3835 ** sqlite3_context object. ^A pointer to an sqlite3_context object 3836 ** is always first parameter to [application-defined SQL functions]. 3837 ** The application-defined SQL function implementation will pass this 3838 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3839 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3840 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3841 ** and/or [sqlite3_set_auxdata()]. 3842 */ 3843 typedef struct sqlite3_context sqlite3_context; 3844 3845 /* 3846 ** CAPI3REF: Binding Values To Prepared Statements 3847 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3848 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3849 ** METHOD: sqlite3_stmt 3850 ** 3851 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3852 ** literals may be replaced by a [parameter] that matches one of following 3853 ** templates: 3854 ** 3855 ** <ul> 3856 ** <li> ? 3857 ** <li> ?NNN 3858 ** <li> :VVV 3859 ** <li> @VVV 3860 ** <li> $VVV 3861 ** </ul> 3862 ** 3863 ** In the templates above, NNN represents an integer literal, 3864 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 3865 ** parameters (also called "host parameter names" or "SQL parameters") 3866 ** can be set using the sqlite3_bind_*() routines defined here. 3867 ** 3868 ** ^The first argument to the sqlite3_bind_*() routines is always 3869 ** a pointer to the [sqlite3_stmt] object returned from 3870 ** [sqlite3_prepare_v2()] or its variants. 3871 ** 3872 ** ^The second argument is the index of the SQL parameter to be set. 3873 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 3874 ** SQL parameter is used more than once, second and subsequent 3875 ** occurrences have the same index as the first occurrence. 3876 ** ^The index for named parameters can be looked up using the 3877 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 3878 ** for "?NNN" parameters is the value of NNN. 3879 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 3880 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3881 ** 3882 ** ^The third argument is the value to bind to the parameter. 3883 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3884 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3885 ** is ignored and the end result is the same as sqlite3_bind_null(). 3886 ** 3887 ** ^(In those routines that have a fourth argument, its value is the 3888 ** number of bytes in the parameter. To be clear: the value is the 3889 ** number of <u>bytes</u> in the value, not the number of characters.)^ 3890 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3891 ** is negative, then the length of the string is 3892 ** the number of bytes up to the first zero terminator. 3893 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 3894 ** the behavior is undefined. 3895 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3896 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3897 ** that parameter must be the byte offset 3898 ** where the NUL terminator would occur assuming the string were NUL 3899 ** terminated. If any NUL characters occur at byte offsets less than 3900 ** the value of the fourth parameter then the resulting string value will 3901 ** contain embedded NULs. The result of expressions involving strings 3902 ** with embedded NULs is undefined. 3903 ** 3904 ** ^The fifth argument to the BLOB and string binding interfaces 3905 ** is a destructor used to dispose of the BLOB or 3906 ** string after SQLite has finished with it. ^The destructor is called 3907 ** to dispose of the BLOB or string even if the call to bind API fails. 3908 ** ^If the fifth argument is 3909 ** the special value [SQLITE_STATIC], then SQLite assumes that the 3910 ** information is in static, unmanaged space and does not need to be freed. 3911 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3912 ** SQLite makes its own private copy of the data immediately, before 3913 ** the sqlite3_bind_*() routine returns. 3914 ** 3915 ** ^The sixth argument to sqlite3_bind_text64() must be one of 3916 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3917 ** to specify the encoding of the text in the third parameter. If 3918 ** the sixth argument to sqlite3_bind_text64() is not one of the 3919 ** allowed values shown above, or if the text encoding is different 3920 ** from the encoding specified by the sixth parameter, then the behavior 3921 ** is undefined. 3922 ** 3923 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3924 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3925 ** (just an integer to hold its size) while it is being processed. 3926 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 3927 ** content is later written using 3928 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 3929 ** ^A negative value for the zeroblob results in a zero-length BLOB. 3930 ** 3931 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 3932 ** [prepared statement] S to have an SQL value of NULL, but to also be 3933 ** associated with the pointer P of type T. ^D is either a NULL pointer or 3934 ** a pointer to a destructor function for P. ^SQLite will invoke the 3935 ** destructor D with a single argument of P when it is finished using 3936 ** P. The T parameter should be a static string, preferably a string 3937 ** literal. The sqlite3_bind_pointer() routine is part of the 3938 ** [pointer passing interface] added for SQLite 3.20.0. 3939 ** 3940 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3941 ** for the [prepared statement] or with a prepared statement for which 3942 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3943 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3944 ** routine is passed a [prepared statement] that has been finalized, the 3945 ** result is undefined and probably harmful. 3946 ** 3947 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3948 ** ^Unbound parameters are interpreted as NULL. 3949 ** 3950 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3951 ** [error code] if anything goes wrong. 3952 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3953 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3954 ** [SQLITE_MAX_LENGTH]. 3955 ** ^[SQLITE_RANGE] is returned if the parameter 3956 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3957 ** 3958 ** See also: [sqlite3_bind_parameter_count()], 3959 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3960 */ 3961 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3962 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3963 void(*)(void*)); 3964 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 3965 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 3966 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3967 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 3968 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3969 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3970 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3971 void(*)(void*), unsigned char encoding); 3972 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3973 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 3974 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3975 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 3976 3977 /* 3978 ** CAPI3REF: Number Of SQL Parameters 3979 ** METHOD: sqlite3_stmt 3980 ** 3981 ** ^This routine can be used to find the number of [SQL parameters] 3982 ** in a [prepared statement]. SQL parameters are tokens of the 3983 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3984 ** placeholders for values that are [sqlite3_bind_blob | bound] 3985 ** to the parameters at a later time. 3986 ** 3987 ** ^(This routine actually returns the index of the largest (rightmost) 3988 ** parameter. For all forms except ?NNN, this will correspond to the 3989 ** number of unique parameters. If parameters of the ?NNN form are used, 3990 ** there may be gaps in the list.)^ 3991 ** 3992 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 3993 ** [sqlite3_bind_parameter_name()], and 3994 ** [sqlite3_bind_parameter_index()]. 3995 */ 3996 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 3997 3998 /* 3999 ** CAPI3REF: Name Of A Host Parameter 4000 ** METHOD: sqlite3_stmt 4001 ** 4002 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4003 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4004 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4005 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4006 ** respectively. 4007 ** In other words, the initial ":" or "$" or "@" or "?" 4008 ** is included as part of the name.)^ 4009 ** ^Parameters of the form "?" without a following integer have no name 4010 ** and are referred to as "nameless" or "anonymous parameters". 4011 ** 4012 ** ^The first host parameter has an index of 1, not 0. 4013 ** 4014 ** ^If the value N is out of range or if the N-th parameter is 4015 ** nameless, then NULL is returned. ^The returned string is 4016 ** always in UTF-8 encoding even if the named parameter was 4017 ** originally specified as UTF-16 in [sqlite3_prepare16()], 4018 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4019 ** 4020 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4021 ** [sqlite3_bind_parameter_count()], and 4022 ** [sqlite3_bind_parameter_index()]. 4023 */ 4024 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4025 4026 /* 4027 ** CAPI3REF: Index Of A Parameter With A Given Name 4028 ** METHOD: sqlite3_stmt 4029 ** 4030 ** ^Return the index of an SQL parameter given its name. ^The 4031 ** index value returned is suitable for use as the second 4032 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4033 ** is returned if no matching parameter is found. ^The parameter 4034 ** name must be given in UTF-8 even if the original statement 4035 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4036 ** [sqlite3_prepare16_v3()]. 4037 ** 4038 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4039 ** [sqlite3_bind_parameter_count()], and 4040 ** [sqlite3_bind_parameter_name()]. 4041 */ 4042 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4043 4044 /* 4045 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4046 ** METHOD: sqlite3_stmt 4047 ** 4048 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4049 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4050 ** ^Use this routine to reset all host parameters to NULL. 4051 */ 4052 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4053 4054 /* 4055 ** CAPI3REF: Number Of Columns In A Result Set 4056 ** METHOD: sqlite3_stmt 4057 ** 4058 ** ^Return the number of columns in the result set returned by the 4059 ** [prepared statement]. ^If this routine returns 0, that means the 4060 ** [prepared statement] returns no data (for example an [UPDATE]). 4061 ** ^However, just because this routine returns a positive number does not 4062 ** mean that one or more rows of data will be returned. ^A SELECT statement 4063 ** will always have a positive sqlite3_column_count() but depending on the 4064 ** WHERE clause constraints and the table content, it might return no rows. 4065 ** 4066 ** See also: [sqlite3_data_count()] 4067 */ 4068 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4069 4070 /* 4071 ** CAPI3REF: Column Names In A Result Set 4072 ** METHOD: sqlite3_stmt 4073 ** 4074 ** ^These routines return the name assigned to a particular column 4075 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4076 ** interface returns a pointer to a zero-terminated UTF-8 string 4077 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 4078 ** UTF-16 string. ^The first parameter is the [prepared statement] 4079 ** that implements the [SELECT] statement. ^The second parameter is the 4080 ** column number. ^The leftmost column is number 0. 4081 ** 4082 ** ^The returned string pointer is valid until either the [prepared statement] 4083 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4084 ** reprepared by the first call to [sqlite3_step()] for a particular run 4085 ** or until the next call to 4086 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4087 ** 4088 ** ^If sqlite3_malloc() fails during the processing of either routine 4089 ** (for example during a conversion from UTF-8 to UTF-16) then a 4090 ** NULL pointer is returned. 4091 ** 4092 ** ^The name of a result column is the value of the "AS" clause for 4093 ** that column, if there is an AS clause. If there is no AS clause 4094 ** then the name of the column is unspecified and may change from 4095 ** one release of SQLite to the next. 4096 */ 4097 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4098 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4099 4100 /* 4101 ** CAPI3REF: Source Of Data In A Query Result 4102 ** METHOD: sqlite3_stmt 4103 ** 4104 ** ^These routines provide a means to determine the database, table, and 4105 ** table column that is the origin of a particular result column in 4106 ** [SELECT] statement. 4107 ** ^The name of the database or table or column can be returned as 4108 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4109 ** the database name, the _table_ routines return the table name, and 4110 ** the origin_ routines return the column name. 4111 ** ^The returned string is valid until the [prepared statement] is destroyed 4112 ** using [sqlite3_finalize()] or until the statement is automatically 4113 ** reprepared by the first call to [sqlite3_step()] for a particular run 4114 ** or until the same information is requested 4115 ** again in a different encoding. 4116 ** 4117 ** ^The names returned are the original un-aliased names of the 4118 ** database, table, and column. 4119 ** 4120 ** ^The first argument to these interfaces is a [prepared statement]. 4121 ** ^These functions return information about the Nth result column returned by 4122 ** the statement, where N is the second function argument. 4123 ** ^The left-most column is column 0 for these routines. 4124 ** 4125 ** ^If the Nth column returned by the statement is an expression or 4126 ** subquery and is not a column value, then all of these functions return 4127 ** NULL. ^These routine might also return NULL if a memory allocation error 4128 ** occurs. ^Otherwise, they return the name of the attached database, table, 4129 ** or column that query result column was extracted from. 4130 ** 4131 ** ^As with all other SQLite APIs, those whose names end with "16" return 4132 ** UTF-16 encoded strings and the other functions return UTF-8. 4133 ** 4134 ** ^These APIs are only available if the library was compiled with the 4135 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4136 ** 4137 ** If two or more threads call one or more of these routines against the same 4138 ** prepared statement and column at the same time then the results are 4139 ** undefined. 4140 ** 4141 ** If two or more threads call one or more 4142 ** [sqlite3_column_database_name | column metadata interfaces] 4143 ** for the same [prepared statement] and result column 4144 ** at the same time then the results are undefined. 4145 */ 4146 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4147 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4148 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4149 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4150 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4151 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4152 4153 /* 4154 ** CAPI3REF: Declared Datatype Of A Query Result 4155 ** METHOD: sqlite3_stmt 4156 ** 4157 ** ^(The first parameter is a [prepared statement]. 4158 ** If this statement is a [SELECT] statement and the Nth column of the 4159 ** returned result set of that [SELECT] is a table column (not an 4160 ** expression or subquery) then the declared type of the table 4161 ** column is returned.)^ ^If the Nth column of the result set is an 4162 ** expression or subquery, then a NULL pointer is returned. 4163 ** ^The returned string is always UTF-8 encoded. 4164 ** 4165 ** ^(For example, given the database schema: 4166 ** 4167 ** CREATE TABLE t1(c1 VARIANT); 4168 ** 4169 ** and the following statement to be compiled: 4170 ** 4171 ** SELECT c1 + 1, c1 FROM t1; 4172 ** 4173 ** this routine would return the string "VARIANT" for the second result 4174 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4175 ** 4176 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4177 ** is declared to contain a particular type does not mean that the 4178 ** data stored in that column is of the declared type. SQLite is 4179 ** strongly typed, but the typing is dynamic not static. ^Type 4180 ** is associated with individual values, not with the containers 4181 ** used to hold those values. 4182 */ 4183 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4184 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4185 4186 /* 4187 ** CAPI3REF: Evaluate An SQL Statement 4188 ** METHOD: sqlite3_stmt 4189 ** 4190 ** After a [prepared statement] has been prepared using any of 4191 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4192 ** or [sqlite3_prepare16_v3()] or one of the legacy 4193 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4194 ** must be called one or more times to evaluate the statement. 4195 ** 4196 ** The details of the behavior of the sqlite3_step() interface depend 4197 ** on whether the statement was prepared using the newer "vX" interfaces 4198 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4199 ** [sqlite3_prepare16_v2()] or the older legacy 4200 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4201 ** new "vX" interface is recommended for new applications but the legacy 4202 ** interface will continue to be supported. 4203 ** 4204 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4205 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4206 ** ^With the "v2" interface, any of the other [result codes] or 4207 ** [extended result codes] might be returned as well. 4208 ** 4209 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4210 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4211 ** or occurs outside of an explicit transaction, then you can retry the 4212 ** statement. If the statement is not a [COMMIT] and occurs within an 4213 ** explicit transaction then you should rollback the transaction before 4214 ** continuing. 4215 ** 4216 ** ^[SQLITE_DONE] means that the statement has finished executing 4217 ** successfully. sqlite3_step() should not be called again on this virtual 4218 ** machine without first calling [sqlite3_reset()] to reset the virtual 4219 ** machine back to its initial state. 4220 ** 4221 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4222 ** is returned each time a new row of data is ready for processing by the 4223 ** caller. The values may be accessed using the [column access functions]. 4224 ** sqlite3_step() is called again to retrieve the next row of data. 4225 ** 4226 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4227 ** violation) has occurred. sqlite3_step() should not be called again on 4228 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4229 ** ^With the legacy interface, a more specific error code (for example, 4230 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4231 ** can be obtained by calling [sqlite3_reset()] on the 4232 ** [prepared statement]. ^In the "v2" interface, 4233 ** the more specific error code is returned directly by sqlite3_step(). 4234 ** 4235 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4236 ** Perhaps it was called on a [prepared statement] that has 4237 ** already been [sqlite3_finalize | finalized] or on one that had 4238 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4239 ** be the case that the same database connection is being used by two or 4240 ** more threads at the same moment in time. 4241 ** 4242 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4243 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4244 ** other than [SQLITE_ROW] before any subsequent invocation of 4245 ** sqlite3_step(). Failure to reset the prepared statement using 4246 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4247 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4248 ** sqlite3_step() began 4249 ** calling [sqlite3_reset()] automatically in this circumstance rather 4250 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4251 ** break because any application that ever receives an SQLITE_MISUSE error 4252 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4253 ** can be used to restore the legacy behavior. 4254 ** 4255 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4256 ** API always returns a generic error code, [SQLITE_ERROR], following any 4257 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4258 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4259 ** specific [error codes] that better describes the error. 4260 ** We admit that this is a goofy design. The problem has been fixed 4261 ** with the "v2" interface. If you prepare all of your SQL statements 4262 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4263 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4264 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4265 ** then the more specific [error codes] are returned directly 4266 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4267 */ 4268 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4269 4270 /* 4271 ** CAPI3REF: Number of columns in a result set 4272 ** METHOD: sqlite3_stmt 4273 ** 4274 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4275 ** current row of the result set of [prepared statement] P. 4276 ** ^If prepared statement P does not have results ready to return 4277 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4278 ** interfaces) then sqlite3_data_count(P) returns 0. 4279 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4280 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4281 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4282 ** will return non-zero if previous call to [sqlite3_step](P) returned 4283 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4284 ** where it always returns zero since each step of that multi-step 4285 ** pragma returns 0 columns of data. 4286 ** 4287 ** See also: [sqlite3_column_count()] 4288 */ 4289 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4290 4291 /* 4292 ** CAPI3REF: Fundamental Datatypes 4293 ** KEYWORDS: SQLITE_TEXT 4294 ** 4295 ** ^(Every value in SQLite has one of five fundamental datatypes: 4296 ** 4297 ** <ul> 4298 ** <li> 64-bit signed integer 4299 ** <li> 64-bit IEEE floating point number 4300 ** <li> string 4301 ** <li> BLOB 4302 ** <li> NULL 4303 ** </ul>)^ 4304 ** 4305 ** These constants are codes for each of those types. 4306 ** 4307 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4308 ** for a completely different meaning. Software that links against both 4309 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4310 ** SQLITE_TEXT. 4311 */ 4312 #define SQLITE_INTEGER 1 4313 #define SQLITE_FLOAT 2 4314 #define SQLITE_BLOB 4 4315 #define SQLITE_NULL 5 4316 #ifdef SQLITE_TEXT 4317 # undef SQLITE_TEXT 4318 #else 4319 # define SQLITE_TEXT 3 4320 #endif 4321 #define SQLITE3_TEXT 3 4322 4323 /* 4324 ** CAPI3REF: Result Values From A Query 4325 ** KEYWORDS: {column access functions} 4326 ** METHOD: sqlite3_stmt 4327 ** 4328 ** <b>Summary:</b> 4329 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4330 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4331 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4332 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4333 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4334 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4335 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4336 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4337 ** [sqlite3_value|unprotected sqlite3_value] object. 4338 ** <tr><td> <td> <td> 4339 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4340 ** or a UTF-8 TEXT result in bytes 4341 ** <tr><td><b>sqlite3_column_bytes16 </b> 4342 ** <td>→ <td>Size of UTF-16 4343 ** TEXT in bytes 4344 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4345 ** datatype of the result 4346 ** </table></blockquote> 4347 ** 4348 ** <b>Details:</b> 4349 ** 4350 ** ^These routines return information about a single column of the current 4351 ** result row of a query. ^In every case the first argument is a pointer 4352 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4353 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4354 ** and the second argument is the index of the column for which information 4355 ** should be returned. ^The leftmost column of the result set has the index 0. 4356 ** ^The number of columns in the result can be determined using 4357 ** [sqlite3_column_count()]. 4358 ** 4359 ** If the SQL statement does not currently point to a valid row, or if the 4360 ** column index is out of range, the result is undefined. 4361 ** These routines may only be called when the most recent call to 4362 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4363 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4364 ** If any of these routines are called after [sqlite3_reset()] or 4365 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4366 ** something other than [SQLITE_ROW], the results are undefined. 4367 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4368 ** are called from a different thread while any of these routines 4369 ** are pending, then the results are undefined. 4370 ** 4371 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4372 ** each return the value of a result column in a specific data format. If 4373 ** the result column is not initially in the requested format (for example, 4374 ** if the query returns an integer but the sqlite3_column_text() interface 4375 ** is used to extract the value) then an automatic type conversion is performed. 4376 ** 4377 ** ^The sqlite3_column_type() routine returns the 4378 ** [SQLITE_INTEGER | datatype code] for the initial data type 4379 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4380 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4381 ** The return value of sqlite3_column_type() can be used to decide which 4382 ** of the first six interface should be used to extract the column value. 4383 ** The value returned by sqlite3_column_type() is only meaningful if no 4384 ** automatic type conversions have occurred for the value in question. 4385 ** After a type conversion, the result of calling sqlite3_column_type() 4386 ** is undefined, though harmless. Future 4387 ** versions of SQLite may change the behavior of sqlite3_column_type() 4388 ** following a type conversion. 4389 ** 4390 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4391 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 4392 ** of that BLOB or string. 4393 ** 4394 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4395 ** routine returns the number of bytes in that BLOB or string. 4396 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4397 ** the string to UTF-8 and then returns the number of bytes. 4398 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 4399 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4400 ** the number of bytes in that string. 4401 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4402 ** 4403 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4404 ** routine returns the number of bytes in that BLOB or string. 4405 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4406 ** the string to UTF-16 and then returns the number of bytes. 4407 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4408 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4409 ** the number of bytes in that string. 4410 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4411 ** 4412 ** ^The values returned by [sqlite3_column_bytes()] and 4413 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4414 ** of the string. ^For clarity: the values returned by 4415 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4416 ** bytes in the string, not the number of characters. 4417 ** 4418 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4419 ** even empty strings, are always zero-terminated. ^The return 4420 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4421 ** 4422 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4423 ** [unprotected sqlite3_value] object. In a multithreaded environment, 4424 ** an unprotected sqlite3_value object may only be used safely with 4425 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4426 ** If the [unprotected sqlite3_value] object returned by 4427 ** [sqlite3_column_value()] is used in any other way, including calls 4428 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4429 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4430 ** Hence, the sqlite3_column_value() interface 4431 ** is normally only useful within the implementation of 4432 ** [application-defined SQL functions] or [virtual tables], not within 4433 ** top-level application code. 4434 ** 4435 ** The these routines may attempt to convert the datatype of the result. 4436 ** ^For example, if the internal representation is FLOAT and a text result 4437 ** is requested, [sqlite3_snprintf()] is used internally to perform the 4438 ** conversion automatically. ^(The following table details the conversions 4439 ** that are applied: 4440 ** 4441 ** <blockquote> 4442 ** <table border="1"> 4443 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4444 ** 4445 ** <tr><td> NULL <td> INTEGER <td> Result is 0 4446 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4447 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4448 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4449 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4450 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4451 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4452 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4453 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4454 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4455 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4456 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4457 ** <tr><td> TEXT <td> BLOB <td> No change 4458 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4459 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4460 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4461 ** </table> 4462 ** </blockquote>)^ 4463 ** 4464 ** Note that when type conversions occur, pointers returned by prior 4465 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4466 ** sqlite3_column_text16() may be invalidated. 4467 ** Type conversions and pointer invalidations might occur 4468 ** in the following cases: 4469 ** 4470 ** <ul> 4471 ** <li> The initial content is a BLOB and sqlite3_column_text() or 4472 ** sqlite3_column_text16() is called. A zero-terminator might 4473 ** need to be added to the string.</li> 4474 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4475 ** sqlite3_column_text16() is called. The content must be converted 4476 ** to UTF-16.</li> 4477 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4478 ** sqlite3_column_text() is called. The content must be converted 4479 ** to UTF-8.</li> 4480 ** </ul> 4481 ** 4482 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4483 ** not invalidate a prior pointer, though of course the content of the buffer 4484 ** that the prior pointer references will have been modified. Other kinds 4485 ** of conversion are done in place when it is possible, but sometimes they 4486 ** are not possible and in those cases prior pointers are invalidated. 4487 ** 4488 ** The safest policy is to invoke these routines 4489 ** in one of the following ways: 4490 ** 4491 ** <ul> 4492 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4493 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4494 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4495 ** </ul> 4496 ** 4497 ** In other words, you should call sqlite3_column_text(), 4498 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4499 ** into the desired format, then invoke sqlite3_column_bytes() or 4500 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4501 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4502 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4503 ** with calls to sqlite3_column_bytes(). 4504 ** 4505 ** ^The pointers returned are valid until a type conversion occurs as 4506 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4507 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4508 ** and BLOBs is freed automatically. Do not pass the pointers returned 4509 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4510 ** [sqlite3_free()]. 4511 ** 4512 ** ^(If a memory allocation error occurs during the evaluation of any 4513 ** of these routines, a default value is returned. The default value 4514 ** is either the integer 0, the floating point number 0.0, or a NULL 4515 ** pointer. Subsequent calls to [sqlite3_errcode()] will return 4516 ** [SQLITE_NOMEM].)^ 4517 */ 4518 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4519 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4520 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4521 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4522 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4523 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4524 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4525 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4526 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4527 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4528 4529 /* 4530 ** CAPI3REF: Destroy A Prepared Statement Object 4531 ** DESTRUCTOR: sqlite3_stmt 4532 ** 4533 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4534 ** ^If the most recent evaluation of the statement encountered no errors 4535 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 4536 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4537 ** sqlite3_finalize(S) returns the appropriate [error code] or 4538 ** [extended error code]. 4539 ** 4540 ** ^The sqlite3_finalize(S) routine can be called at any point during 4541 ** the life cycle of [prepared statement] S: 4542 ** before statement S is ever evaluated, after 4543 ** one or more calls to [sqlite3_reset()], or after any call 4544 ** to [sqlite3_step()] regardless of whether or not the statement has 4545 ** completed execution. 4546 ** 4547 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4548 ** 4549 ** The application must finalize every [prepared statement] in order to avoid 4550 ** resource leaks. It is a grievous error for the application to try to use 4551 ** a prepared statement after it has been finalized. Any use of a prepared 4552 ** statement after it has been finalized can result in undefined and 4553 ** undesirable behavior such as segfaults and heap corruption. 4554 */ 4555 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 4556 4557 /* 4558 ** CAPI3REF: Reset A Prepared Statement Object 4559 ** METHOD: sqlite3_stmt 4560 ** 4561 ** The sqlite3_reset() function is called to reset a [prepared statement] 4562 ** object back to its initial state, ready to be re-executed. 4563 ** ^Any SQL statement variables that had values bound to them using 4564 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4565 ** Use [sqlite3_clear_bindings()] to reset the bindings. 4566 ** 4567 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4568 ** back to the beginning of its program. 4569 ** 4570 ** ^If the most recent call to [sqlite3_step(S)] for the 4571 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4572 ** or if [sqlite3_step(S)] has never before been called on S, 4573 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4574 ** 4575 ** ^If the most recent call to [sqlite3_step(S)] for the 4576 ** [prepared statement] S indicated an error, then 4577 ** [sqlite3_reset(S)] returns an appropriate [error code]. 4578 ** 4579 ** ^The [sqlite3_reset(S)] interface does not change the values 4580 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4581 */ 4582 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 4583 4584 /* 4585 ** CAPI3REF: Create Or Redefine SQL Functions 4586 ** KEYWORDS: {function creation routines} 4587 ** KEYWORDS: {application-defined SQL function} 4588 ** KEYWORDS: {application-defined SQL functions} 4589 ** METHOD: sqlite3 4590 ** 4591 ** ^These functions (collectively known as "function creation routines") 4592 ** are used to add SQL functions or aggregates or to redefine the behavior 4593 ** of existing SQL functions or aggregates. The only differences between 4594 ** these routines are the text encoding expected for 4595 ** the second parameter (the name of the function being created) 4596 ** and the presence or absence of a destructor callback for 4597 ** the application data pointer. 4598 ** 4599 ** ^The first parameter is the [database connection] to which the SQL 4600 ** function is to be added. ^If an application uses more than one database 4601 ** connection then application-defined SQL functions must be added 4602 ** to each database connection separately. 4603 ** 4604 ** ^The second parameter is the name of the SQL function to be created or 4605 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4606 ** representation, exclusive of the zero-terminator. ^Note that the name 4607 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4608 ** ^Any attempt to create a function with a longer name 4609 ** will result in [SQLITE_MISUSE] being returned. 4610 ** 4611 ** ^The third parameter (nArg) 4612 ** is the number of arguments that the SQL function or 4613 ** aggregate takes. ^If this parameter is -1, then the SQL function or 4614 ** aggregate may take any number of arguments between 0 and the limit 4615 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4616 ** parameter is less than -1 or greater than 127 then the behavior is 4617 ** undefined. 4618 ** 4619 ** ^The fourth parameter, eTextRep, specifies what 4620 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4621 ** its parameters. The application should set this parameter to 4622 ** [SQLITE_UTF16LE] if the function implementation invokes 4623 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4624 ** implementation invokes [sqlite3_value_text16be()] on an input, or 4625 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4626 ** otherwise. ^The same SQL function may be registered multiple times using 4627 ** different preferred text encodings, with different implementations for 4628 ** each encoding. 4629 ** ^When multiple implementations of the same function are available, SQLite 4630 ** will pick the one that involves the least amount of data conversion. 4631 ** 4632 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4633 ** to signal that the function will always return the same result given 4634 ** the same inputs within a single SQL statement. Most SQL functions are 4635 ** deterministic. The built-in [random()] SQL function is an example of a 4636 ** function that is not deterministic. The SQLite query planner is able to 4637 ** perform additional optimizations on deterministic functions, so use 4638 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4639 ** 4640 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4641 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 4642 ** 4643 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4644 ** pointers to C-language functions that implement the SQL function or 4645 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4646 ** callback only; NULL pointers must be passed as the xStep and xFinal 4647 ** parameters. ^An aggregate SQL function requires an implementation of xStep 4648 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4649 ** SQL function or aggregate, pass NULL pointers for all three function 4650 ** callbacks. 4651 ** 4652 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4653 ** then it is destructor for the application data pointer. 4654 ** The destructor is invoked when the function is deleted, either by being 4655 ** overloaded or when the database connection closes.)^ 4656 ** ^The destructor is also invoked if the call to 4657 ** sqlite3_create_function_v2() fails. 4658 ** ^When the destructor callback of the tenth parameter is invoked, it 4659 ** is passed a single argument which is a copy of the application data 4660 ** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4661 ** 4662 ** ^It is permitted to register multiple implementations of the same 4663 ** functions with the same name but with either differing numbers of 4664 ** arguments or differing preferred text encodings. ^SQLite will use 4665 ** the implementation that most closely matches the way in which the 4666 ** SQL function is used. ^A function implementation with a non-negative 4667 ** nArg parameter is a better match than a function implementation with 4668 ** a negative nArg. ^A function where the preferred text encoding 4669 ** matches the database encoding is a better 4670 ** match than a function where the encoding is different. 4671 ** ^A function where the encoding difference is between UTF16le and UTF16be 4672 ** is a closer match than a function where the encoding difference is 4673 ** between UTF8 and UTF16. 4674 ** 4675 ** ^Built-in functions may be overloaded by new application-defined functions. 4676 ** 4677 ** ^An application-defined function is permitted to call other 4678 ** SQLite interfaces. However, such calls must not 4679 ** close the database connection nor finalize or reset the prepared 4680 ** statement in which the function is running. 4681 */ 4682 SQLITE_API int sqlite3_create_function( 4683 sqlite3 *db, 4684 const char *zFunctionName, 4685 int nArg, 4686 int eTextRep, 4687 void *pApp, 4688 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4689 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4690 void (*xFinal)(sqlite3_context*) 4691 ); 4692 SQLITE_API int sqlite3_create_function16( 4693 sqlite3 *db, 4694 const void *zFunctionName, 4695 int nArg, 4696 int eTextRep, 4697 void *pApp, 4698 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4699 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4700 void (*xFinal)(sqlite3_context*) 4701 ); 4702 SQLITE_API int sqlite3_create_function_v2( 4703 sqlite3 *db, 4704 const char *zFunctionName, 4705 int nArg, 4706 int eTextRep, 4707 void *pApp, 4708 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4709 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4710 void (*xFinal)(sqlite3_context*), 4711 void(*xDestroy)(void*) 4712 ); 4713 4714 /* 4715 ** CAPI3REF: Text Encodings 4716 ** 4717 ** These constant define integer codes that represent the various 4718 ** text encodings supported by SQLite. 4719 */ 4720 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4721 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4722 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4723 #define SQLITE_UTF16 4 /* Use native byte order */ 4724 #define SQLITE_ANY 5 /* Deprecated */ 4725 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4726 4727 /* 4728 ** CAPI3REF: Function Flags 4729 ** 4730 ** These constants may be ORed together with the 4731 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4732 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4733 ** [sqlite3_create_function_v2()]. 4734 */ 4735 #define SQLITE_DETERMINISTIC 0x800 4736 4737 /* 4738 ** CAPI3REF: Deprecated Functions 4739 ** DEPRECATED 4740 ** 4741 ** These functions are [deprecated]. In order to maintain 4742 ** backwards compatibility with older code, these functions continue 4743 ** to be supported. However, new applications should avoid 4744 ** the use of these functions. To encourage programmers to avoid 4745 ** these functions, we will not explain what they do. 4746 */ 4747 #ifndef SQLITE_OMIT_DEPRECATED 4748 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4749 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4750 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4751 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 4752 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4753 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4754 void*,sqlite3_int64); 4755 #endif 4756 4757 /* 4758 ** CAPI3REF: Obtaining SQL Values 4759 ** METHOD: sqlite3_value 4760 ** 4761 ** <b>Summary:</b> 4762 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4763 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 4764 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 4765 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 4766 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 4767 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 4768 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 4769 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 4770 ** the native byteorder 4771 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 4772 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 4773 ** <tr><td> <td> <td> 4774 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 4775 ** or a UTF-8 TEXT in bytes 4776 ** <tr><td><b>sqlite3_value_bytes16 </b> 4777 ** <td>→ <td>Size of UTF-16 4778 ** TEXT in bytes 4779 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 4780 ** datatype of the value 4781 ** <tr><td><b>sqlite3_value_numeric_type </b> 4782 ** <td>→ <td>Best numeric datatype of the value 4783 ** </table></blockquote> 4784 ** 4785 ** <b>Details:</b> 4786 ** 4787 ** These routines extract type, size, and content information from 4788 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 4789 ** are used to pass parameter information into implementation of 4790 ** [application-defined SQL functions] and [virtual tables]. 4791 ** 4792 ** These routines work only with [protected sqlite3_value] objects. 4793 ** Any attempt to use these routines on an [unprotected sqlite3_value] 4794 ** is not threadsafe. 4795 ** 4796 ** ^These routines work just like the corresponding [column access functions] 4797 ** except that these routines take a single [protected sqlite3_value] object 4798 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4799 ** 4800 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4801 ** in the native byte-order of the host machine. ^The 4802 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4803 ** extract UTF-16 strings as big-endian and little-endian respectively. 4804 ** 4805 ** ^If [sqlite3_value] object V was initialized 4806 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 4807 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 4808 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 4809 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 4810 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 4811 ** 4812 ** ^(The sqlite3_value_type(V) interface returns the 4813 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 4814 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 4815 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 4816 ** Other interfaces might change the datatype for an sqlite3_value object. 4817 ** For example, if the datatype is initially SQLITE_INTEGER and 4818 ** sqlite3_value_text(V) is called to extract a text value for that 4819 ** integer, then subsequent calls to sqlite3_value_type(V) might return 4820 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 4821 ** occurs is undefined and may change from one release of SQLite to the next. 4822 ** 4823 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 4824 ** numeric affinity to the value. This means that an attempt is 4825 ** made to convert the value to an integer or floating point. If 4826 ** such a conversion is possible without loss of information (in other 4827 ** words, if the value is a string that looks like a number) 4828 ** then the conversion is performed. Otherwise no conversion occurs. 4829 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4830 ** 4831 ** Please pay particular attention to the fact that the pointer returned 4832 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4833 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4834 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4835 ** or [sqlite3_value_text16()]. 4836 ** 4837 ** These routines must be called from the same thread as 4838 ** the SQL function that supplied the [sqlite3_value*] parameters. 4839 */ 4840 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 4841 SQLITE_API double sqlite3_value_double(sqlite3_value*); 4842 SQLITE_API int sqlite3_value_int(sqlite3_value*); 4843 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4844 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 4845 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 4846 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 4847 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 4848 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 4849 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 4850 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 4851 SQLITE_API int sqlite3_value_type(sqlite3_value*); 4852 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 4853 4854 /* 4855 ** CAPI3REF: Finding The Subtype Of SQL Values 4856 ** METHOD: sqlite3_value 4857 ** 4858 ** The sqlite3_value_subtype(V) function returns the subtype for 4859 ** an [application-defined SQL function] argument V. The subtype 4860 ** information can be used to pass a limited amount of context from 4861 ** one SQL function to another. Use the [sqlite3_result_subtype()] 4862 ** routine to set the subtype for the return value of an SQL function. 4863 */ 4864 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 4865 4866 /* 4867 ** CAPI3REF: Copy And Free SQL Values 4868 ** METHOD: sqlite3_value 4869 ** 4870 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 4871 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 4872 ** is a [protected sqlite3_value] object even if the input is not. 4873 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 4874 ** memory allocation fails. 4875 ** 4876 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 4877 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 4878 ** then sqlite3_value_free(V) is a harmless no-op. 4879 */ 4880 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 4881 SQLITE_API void sqlite3_value_free(sqlite3_value*); 4882 4883 /* 4884 ** CAPI3REF: Obtain Aggregate Function Context 4885 ** METHOD: sqlite3_context 4886 ** 4887 ** Implementations of aggregate SQL functions use this 4888 ** routine to allocate memory for storing their state. 4889 ** 4890 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4891 ** for a particular aggregate function, SQLite 4892 ** allocates N of memory, zeroes out that memory, and returns a pointer 4893 ** to the new memory. ^On second and subsequent calls to 4894 ** sqlite3_aggregate_context() for the same aggregate function instance, 4895 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 4896 ** called once for each invocation of the xStep callback and then one 4897 ** last time when the xFinal callback is invoked. ^(When no rows match 4898 ** an aggregate query, the xStep() callback of the aggregate function 4899 ** implementation is never called and xFinal() is called exactly once. 4900 ** In those cases, sqlite3_aggregate_context() might be called for the 4901 ** first time from within xFinal().)^ 4902 ** 4903 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4904 ** when first called if N is less than or equal to zero or if a memory 4905 ** allocate error occurs. 4906 ** 4907 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4908 ** determined by the N parameter on first successful call. Changing the 4909 ** value of N in subsequent call to sqlite3_aggregate_context() within 4910 ** the same aggregate function instance will not resize the memory 4911 ** allocation.)^ Within the xFinal callback, it is customary to set 4912 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4913 ** pointless memory allocations occur. 4914 ** 4915 ** ^SQLite automatically frees the memory allocated by 4916 ** sqlite3_aggregate_context() when the aggregate query concludes. 4917 ** 4918 ** The first parameter must be a copy of the 4919 ** [sqlite3_context | SQL function context] that is the first parameter 4920 ** to the xStep or xFinal callback routine that implements the aggregate 4921 ** function. 4922 ** 4923 ** This routine must be called from the same thread in which 4924 ** the aggregate SQL function is running. 4925 */ 4926 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4927 4928 /* 4929 ** CAPI3REF: User Data For Functions 4930 ** METHOD: sqlite3_context 4931 ** 4932 ** ^The sqlite3_user_data() interface returns a copy of 4933 ** the pointer that was the pUserData parameter (the 5th parameter) 4934 ** of the [sqlite3_create_function()] 4935 ** and [sqlite3_create_function16()] routines that originally 4936 ** registered the application defined function. 4937 ** 4938 ** This routine must be called from the same thread in which 4939 ** the application-defined function is running. 4940 */ 4941 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 4942 4943 /* 4944 ** CAPI3REF: Database Connection For Functions 4945 ** METHOD: sqlite3_context 4946 ** 4947 ** ^The sqlite3_context_db_handle() interface returns a copy of 4948 ** the pointer to the [database connection] (the 1st parameter) 4949 ** of the [sqlite3_create_function()] 4950 ** and [sqlite3_create_function16()] routines that originally 4951 ** registered the application defined function. 4952 */ 4953 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4954 4955 /* 4956 ** CAPI3REF: Function Auxiliary Data 4957 ** METHOD: sqlite3_context 4958 ** 4959 ** These functions may be used by (non-aggregate) SQL functions to 4960 ** associate metadata with argument values. If the same value is passed to 4961 ** multiple invocations of the same SQL function during query execution, under 4962 ** some circumstances the associated metadata may be preserved. An example 4963 ** of where this might be useful is in a regular-expression matching 4964 ** function. The compiled version of the regular expression can be stored as 4965 ** metadata associated with the pattern string. 4966 ** Then as long as the pattern string remains the same, 4967 ** the compiled regular expression can be reused on multiple 4968 ** invocations of the same function. 4969 ** 4970 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 4971 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 4972 ** value to the application-defined function. ^N is zero for the left-most 4973 ** function argument. ^If there is no metadata 4974 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 4975 ** returns a NULL pointer. 4976 ** 4977 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4978 ** argument of the application-defined function. ^Subsequent 4979 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4980 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4981 ** NULL if the metadata has been discarded. 4982 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4983 ** SQLite will invoke the destructor function X with parameter P exactly 4984 ** once, when the metadata is discarded. 4985 ** SQLite is free to discard the metadata at any time, including: <ul> 4986 ** <li> ^(when the corresponding function parameter changes)^, or 4987 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4988 ** SQL statement)^, or 4989 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 4990 ** parameter)^, or 4991 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 4992 ** allocation error occurs.)^ </ul> 4993 ** 4994 ** Note the last bullet in particular. The destructor X in 4995 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4996 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4997 ** should be called near the end of the function implementation and the 4998 ** function implementation should not make any use of P after 4999 ** sqlite3_set_auxdata() has been called. 5000 ** 5001 ** ^(In practice, metadata is preserved between function calls for 5002 ** function parameters that are compile-time constants, including literal 5003 ** values and [parameters] and expressions composed from the same.)^ 5004 ** 5005 ** The value of the N parameter to these interfaces should be non-negative. 5006 ** Future enhancements may make use of negative N values to define new 5007 ** kinds of function caching behavior. 5008 ** 5009 ** These routines must be called from the same thread in which 5010 ** the SQL function is running. 5011 */ 5012 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5013 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5014 5015 5016 /* 5017 ** CAPI3REF: Constants Defining Special Destructor Behavior 5018 ** 5019 ** These are special values for the destructor that is passed in as the 5020 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5021 ** argument is SQLITE_STATIC, it means that the content pointer is constant 5022 ** and will never change. It does not need to be destroyed. ^The 5023 ** SQLITE_TRANSIENT value means that the content will likely change in 5024 ** the near future and that SQLite should make its own private copy of 5025 ** the content before returning. 5026 ** 5027 ** The typedef is necessary to work around problems in certain 5028 ** C++ compilers. 5029 */ 5030 typedef void (*sqlite3_destructor_type)(void*); 5031 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 5032 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5033 5034 /* 5035 ** CAPI3REF: Setting The Result Of An SQL Function 5036 ** METHOD: sqlite3_context 5037 ** 5038 ** These routines are used by the xFunc or xFinal callbacks that 5039 ** implement SQL functions and aggregates. See 5040 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 5041 ** for additional information. 5042 ** 5043 ** These functions work very much like the [parameter binding] family of 5044 ** functions used to bind values to host parameters in prepared statements. 5045 ** Refer to the [SQL parameter] documentation for additional information. 5046 ** 5047 ** ^The sqlite3_result_blob() interface sets the result from 5048 ** an application-defined function to be the BLOB whose content is pointed 5049 ** to by the second parameter and which is N bytes long where N is the 5050 ** third parameter. 5051 ** 5052 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5053 ** interfaces set the result of the application-defined function to be 5054 ** a BLOB containing all zero bytes and N bytes in size. 5055 ** 5056 ** ^The sqlite3_result_double() interface sets the result from 5057 ** an application-defined function to be a floating point value specified 5058 ** by its 2nd argument. 5059 ** 5060 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5061 ** cause the implemented SQL function to throw an exception. 5062 ** ^SQLite uses the string pointed to by the 5063 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5064 ** as the text of an error message. ^SQLite interprets the error 5065 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 5066 ** interprets the string from sqlite3_result_error16() as UTF-16 in native 5067 ** byte order. ^If the third parameter to sqlite3_result_error() 5068 ** or sqlite3_result_error16() is negative then SQLite takes as the error 5069 ** message all text up through the first zero character. 5070 ** ^If the third parameter to sqlite3_result_error() or 5071 ** sqlite3_result_error16() is non-negative then SQLite takes that many 5072 ** bytes (not characters) from the 2nd parameter as the error message. 5073 ** ^The sqlite3_result_error() and sqlite3_result_error16() 5074 ** routines make a private copy of the error message text before 5075 ** they return. Hence, the calling function can deallocate or 5076 ** modify the text after they return without harm. 5077 ** ^The sqlite3_result_error_code() function changes the error code 5078 ** returned by SQLite as a result of an error in a function. ^By default, 5079 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5080 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5081 ** 5082 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5083 ** error indicating that a string or BLOB is too long to represent. 5084 ** 5085 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5086 ** error indicating that a memory allocation failed. 5087 ** 5088 ** ^The sqlite3_result_int() interface sets the return value 5089 ** of the application-defined function to be the 32-bit signed integer 5090 ** value given in the 2nd argument. 5091 ** ^The sqlite3_result_int64() interface sets the return value 5092 ** of the application-defined function to be the 64-bit signed integer 5093 ** value given in the 2nd argument. 5094 ** 5095 ** ^The sqlite3_result_null() interface sets the return value 5096 ** of the application-defined function to be NULL. 5097 ** 5098 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 5099 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5100 ** set the return value of the application-defined function to be 5101 ** a text string which is represented as UTF-8, UTF-16 native byte order, 5102 ** UTF-16 little endian, or UTF-16 big endian, respectively. 5103 ** ^The sqlite3_result_text64() interface sets the return value of an 5104 ** application-defined function to be a text string in an encoding 5105 ** specified by the fifth (and last) parameter, which must be one 5106 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5107 ** ^SQLite takes the text result from the application from 5108 ** the 2nd parameter of the sqlite3_result_text* interfaces. 5109 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5110 ** is negative, then SQLite takes result text from the 2nd parameter 5111 ** through the first zero character. 5112 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5113 ** is non-negative, then as many bytes (not characters) of the text 5114 ** pointed to by the 2nd parameter are taken as the application-defined 5115 ** function result. If the 3rd parameter is non-negative, then it 5116 ** must be the byte offset into the string where the NUL terminator would 5117 ** appear if the string where NUL terminated. If any NUL characters occur 5118 ** in the string at a byte offset that is less than the value of the 3rd 5119 ** parameter, then the resulting string will contain embedded NULs and the 5120 ** result of expressions operating on strings with embedded NULs is undefined. 5121 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5122 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5123 ** function as the destructor on the text or BLOB result when it has 5124 ** finished using that result. 5125 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5126 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5127 ** assumes that the text or BLOB result is in constant space and does not 5128 ** copy the content of the parameter nor call a destructor on the content 5129 ** when it has finished using that result. 5130 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5131 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5132 ** then SQLite makes a copy of the result into space obtained 5133 ** from [sqlite3_malloc()] before it returns. 5134 ** 5135 ** ^The sqlite3_result_value() interface sets the result of 5136 ** the application-defined function to be a copy of the 5137 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5138 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5139 ** so that the [sqlite3_value] specified in the parameter may change or 5140 ** be deallocated after sqlite3_result_value() returns without harm. 5141 ** ^A [protected sqlite3_value] object may always be used where an 5142 ** [unprotected sqlite3_value] object is required, so either 5143 ** kind of [sqlite3_value] object can be used with this interface. 5144 ** 5145 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5146 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5147 ** also associates the host-language pointer P or type T with that 5148 ** NULL value such that the pointer can be retrieved within an 5149 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 5150 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 5151 ** for the P parameter. ^SQLite invokes D with P as its only argument 5152 ** when SQLite is finished with P. The T parameter should be a static 5153 ** string and preferably a string literal. The sqlite3_result_pointer() 5154 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5155 ** 5156 ** If these routines are called from within the different thread 5157 ** than the one containing the application-defined function that received 5158 ** the [sqlite3_context] pointer, the results are undefined. 5159 */ 5160 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5161 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5162 sqlite3_uint64,void(*)(void*)); 5163 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 5164 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 5165 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 5166 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 5167 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5168 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5169 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5170 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5171 SQLITE_API void sqlite3_result_null(sqlite3_context*); 5172 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5173 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5174 void(*)(void*), unsigned char encoding); 5175 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5176 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5177 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5178 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5179 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5180 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 5181 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5182 5183 5184 /* 5185 ** CAPI3REF: Setting The Subtype Of An SQL Function 5186 ** METHOD: sqlite3_context 5187 ** 5188 ** The sqlite3_result_subtype(C,T) function causes the subtype of 5189 ** the result from the [application-defined SQL function] with 5190 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 5191 ** of the subtype T are preserved in current versions of SQLite; 5192 ** higher order bits are discarded. 5193 ** The number of subtype bytes preserved by SQLite might increase 5194 ** in future releases of SQLite. 5195 */ 5196 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5197 5198 /* 5199 ** CAPI3REF: Define New Collating Sequences 5200 ** METHOD: sqlite3 5201 ** 5202 ** ^These functions add, remove, or modify a [collation] associated 5203 ** with the [database connection] specified as the first argument. 5204 ** 5205 ** ^The name of the collation is a UTF-8 string 5206 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5207 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5208 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5209 ** considered to be the same name. 5210 ** 5211 ** ^(The third argument (eTextRep) must be one of the constants: 5212 ** <ul> 5213 ** <li> [SQLITE_UTF8], 5214 ** <li> [SQLITE_UTF16LE], 5215 ** <li> [SQLITE_UTF16BE], 5216 ** <li> [SQLITE_UTF16], or 5217 ** <li> [SQLITE_UTF16_ALIGNED]. 5218 ** </ul>)^ 5219 ** ^The eTextRep argument determines the encoding of strings passed 5220 ** to the collating function callback, xCallback. 5221 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5222 ** force strings to be UTF16 with native byte order. 5223 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5224 ** on an even byte address. 5225 ** 5226 ** ^The fourth argument, pArg, is an application data pointer that is passed 5227 ** through as the first argument to the collating function callback. 5228 ** 5229 ** ^The fifth argument, xCallback, is a pointer to the collating function. 5230 ** ^Multiple collating functions can be registered using the same name but 5231 ** with different eTextRep parameters and SQLite will use whichever 5232 ** function requires the least amount of data transformation. 5233 ** ^If the xCallback argument is NULL then the collating function is 5234 ** deleted. ^When all collating functions having the same name are deleted, 5235 ** that collation is no longer usable. 5236 ** 5237 ** ^The collating function callback is invoked with a copy of the pArg 5238 ** application data pointer and with two strings in the encoding specified 5239 ** by the eTextRep argument. The collating function must return an 5240 ** integer that is negative, zero, or positive 5241 ** if the first string is less than, equal to, or greater than the second, 5242 ** respectively. A collating function must always return the same answer 5243 ** given the same inputs. If two or more collating functions are registered 5244 ** to the same collation name (using different eTextRep values) then all 5245 ** must give an equivalent answer when invoked with equivalent strings. 5246 ** The collating function must obey the following properties for all 5247 ** strings A, B, and C: 5248 ** 5249 ** <ol> 5250 ** <li> If A==B then B==A. 5251 ** <li> If A==B and B==C then A==C. 5252 ** <li> If A<B THEN B>A. 5253 ** <li> If A<B and B<C then A<C. 5254 ** </ol> 5255 ** 5256 ** If a collating function fails any of the above constraints and that 5257 ** collating function is registered and used, then the behavior of SQLite 5258 ** is undefined. 5259 ** 5260 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5261 ** with the addition that the xDestroy callback is invoked on pArg when 5262 ** the collating function is deleted. 5263 ** ^Collating functions are deleted when they are overridden by later 5264 ** calls to the collation creation functions or when the 5265 ** [database connection] is closed using [sqlite3_close()]. 5266 ** 5267 ** ^The xDestroy callback is <u>not</u> called if the 5268 ** sqlite3_create_collation_v2() function fails. Applications that invoke 5269 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5270 ** check the return code and dispose of the application data pointer 5271 ** themselves rather than expecting SQLite to deal with it for them. 5272 ** This is different from every other SQLite interface. The inconsistency 5273 ** is unfortunate but cannot be changed without breaking backwards 5274 ** compatibility. 5275 ** 5276 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5277 */ 5278 SQLITE_API int sqlite3_create_collation( 5279 sqlite3*, 5280 const char *zName, 5281 int eTextRep, 5282 void *pArg, 5283 int(*xCompare)(void*,int,const void*,int,const void*) 5284 ); 5285 SQLITE_API int sqlite3_create_collation_v2( 5286 sqlite3*, 5287 const char *zName, 5288 int eTextRep, 5289 void *pArg, 5290 int(*xCompare)(void*,int,const void*,int,const void*), 5291 void(*xDestroy)(void*) 5292 ); 5293 SQLITE_API int sqlite3_create_collation16( 5294 sqlite3*, 5295 const void *zName, 5296 int eTextRep, 5297 void *pArg, 5298 int(*xCompare)(void*,int,const void*,int,const void*) 5299 ); 5300 5301 /* 5302 ** CAPI3REF: Collation Needed Callbacks 5303 ** METHOD: sqlite3 5304 ** 5305 ** ^To avoid having to register all collation sequences before a database 5306 ** can be used, a single callback function may be registered with the 5307 ** [database connection] to be invoked whenever an undefined collation 5308 ** sequence is required. 5309 ** 5310 ** ^If the function is registered using the sqlite3_collation_needed() API, 5311 ** then it is passed the names of undefined collation sequences as strings 5312 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5313 ** the names are passed as UTF-16 in machine native byte order. 5314 ** ^A call to either function replaces the existing collation-needed callback. 5315 ** 5316 ** ^(When the callback is invoked, the first argument passed is a copy 5317 ** of the second argument to sqlite3_collation_needed() or 5318 ** sqlite3_collation_needed16(). The second argument is the database 5319 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5320 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5321 ** sequence function required. The fourth parameter is the name of the 5322 ** required collation sequence.)^ 5323 ** 5324 ** The callback function should register the desired collation using 5325 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5326 ** [sqlite3_create_collation_v2()]. 5327 */ 5328 SQLITE_API int sqlite3_collation_needed( 5329 sqlite3*, 5330 void*, 5331 void(*)(void*,sqlite3*,int eTextRep,const char*) 5332 ); 5333 SQLITE_API int sqlite3_collation_needed16( 5334 sqlite3*, 5335 void*, 5336 void(*)(void*,sqlite3*,int eTextRep,const void*) 5337 ); 5338 5339 #ifdef SQLITE_HAS_CODEC 5340 /* 5341 ** Specify the key for an encrypted database. This routine should be 5342 ** called right after sqlite3_open(). 5343 ** 5344 ** The code to implement this API is not available in the public release 5345 ** of SQLite. 5346 */ 5347 SQLITE_API int sqlite3_key( 5348 sqlite3 *db, /* Database to be rekeyed */ 5349 const void *pKey, int nKey /* The key */ 5350 ); 5351 SQLITE_API int sqlite3_key_v2( 5352 sqlite3 *db, /* Database to be rekeyed */ 5353 const char *zDbName, /* Name of the database */ 5354 const void *pKey, int nKey /* The key */ 5355 ); 5356 5357 /* 5358 ** Change the key on an open database. If the current database is not 5359 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5360 ** database is decrypted. 5361 ** 5362 ** The code to implement this API is not available in the public release 5363 ** of SQLite. 5364 */ 5365 SQLITE_API int sqlite3_rekey( 5366 sqlite3 *db, /* Database to be rekeyed */ 5367 const void *pKey, int nKey /* The new key */ 5368 ); 5369 SQLITE_API int sqlite3_rekey_v2( 5370 sqlite3 *db, /* Database to be rekeyed */ 5371 const char *zDbName, /* Name of the database */ 5372 const void *pKey, int nKey /* The new key */ 5373 ); 5374 5375 /* 5376 ** Specify the activation key for a SEE database. Unless 5377 ** activated, none of the SEE routines will work. 5378 */ 5379 SQLITE_API void sqlite3_activate_see( 5380 const char *zPassPhrase /* Activation phrase */ 5381 ); 5382 #endif 5383 5384 #ifdef SQLITE_ENABLE_CEROD 5385 /* 5386 ** Specify the activation key for a CEROD database. Unless 5387 ** activated, none of the CEROD routines will work. 5388 */ 5389 SQLITE_API void sqlite3_activate_cerod( 5390 const char *zPassPhrase /* Activation phrase */ 5391 ); 5392 #endif 5393 5394 /* 5395 ** CAPI3REF: Suspend Execution For A Short Time 5396 ** 5397 ** The sqlite3_sleep() function causes the current thread to suspend execution 5398 ** for at least a number of milliseconds specified in its parameter. 5399 ** 5400 ** If the operating system does not support sleep requests with 5401 ** millisecond time resolution, then the time will be rounded up to 5402 ** the nearest second. The number of milliseconds of sleep actually 5403 ** requested from the operating system is returned. 5404 ** 5405 ** ^SQLite implements this interface by calling the xSleep() 5406 ** method of the default [sqlite3_vfs] object. If the xSleep() method 5407 ** of the default VFS is not implemented correctly, or not implemented at 5408 ** all, then the behavior of sqlite3_sleep() may deviate from the description 5409 ** in the previous paragraphs. 5410 */ 5411 SQLITE_API int sqlite3_sleep(int); 5412 5413 /* 5414 ** CAPI3REF: Name Of The Folder Holding Temporary Files 5415 ** 5416 ** ^(If this global variable is made to point to a string which is 5417 ** the name of a folder (a.k.a. directory), then all temporary files 5418 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5419 ** will be placed in that directory.)^ ^If this variable 5420 ** is a NULL pointer, then SQLite performs a search for an appropriate 5421 ** temporary file directory. 5422 ** 5423 ** Applications are strongly discouraged from using this global variable. 5424 ** It is required to set a temporary folder on Windows Runtime (WinRT). 5425 ** But for all other platforms, it is highly recommended that applications 5426 ** neither read nor write this variable. This global variable is a relic 5427 ** that exists for backwards compatibility of legacy applications and should 5428 ** be avoided in new projects. 5429 ** 5430 ** It is not safe to read or modify this variable in more than one 5431 ** thread at a time. It is not safe to read or modify this variable 5432 ** if a [database connection] is being used at the same time in a separate 5433 ** thread. 5434 ** It is intended that this variable be set once 5435 ** as part of process initialization and before any SQLite interface 5436 ** routines have been called and that this variable remain unchanged 5437 ** thereafter. 5438 ** 5439 ** ^The [temp_store_directory pragma] may modify this variable and cause 5440 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5441 ** the [temp_store_directory pragma] always assumes that any string 5442 ** that this variable points to is held in memory obtained from 5443 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5444 ** using [sqlite3_free]. 5445 ** Hence, if this variable is modified directly, either it should be 5446 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5447 ** or else the use of the [temp_store_directory pragma] should be avoided. 5448 ** Except when requested by the [temp_store_directory pragma], SQLite 5449 ** does not free the memory that sqlite3_temp_directory points to. If 5450 ** the application wants that memory to be freed, it must do 5451 ** so itself, taking care to only do so after all [database connection] 5452 ** objects have been destroyed. 5453 ** 5454 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5455 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5456 ** features that require the use of temporary files may fail. Here is an 5457 ** example of how to do this using C++ with the Windows Runtime: 5458 ** 5459 ** <blockquote><pre> 5460 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5461 ** TemporaryFolder->Path->Data(); 5462 ** char zPathBuf[MAX_PATH + 1]; 5463 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 5464 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5465 ** NULL, NULL); 5466 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5467 ** </pre></blockquote> 5468 */ 5469 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 5470 5471 /* 5472 ** CAPI3REF: Name Of The Folder Holding Database Files 5473 ** 5474 ** ^(If this global variable is made to point to a string which is 5475 ** the name of a folder (a.k.a. directory), then all database files 5476 ** specified with a relative pathname and created or accessed by 5477 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5478 ** to be relative to that directory.)^ ^If this variable is a NULL 5479 ** pointer, then SQLite assumes that all database files specified 5480 ** with a relative pathname are relative to the current directory 5481 ** for the process. Only the windows VFS makes use of this global 5482 ** variable; it is ignored by the unix VFS. 5483 ** 5484 ** Changing the value of this variable while a database connection is 5485 ** open can result in a corrupt database. 5486 ** 5487 ** It is not safe to read or modify this variable in more than one 5488 ** thread at a time. It is not safe to read or modify this variable 5489 ** if a [database connection] is being used at the same time in a separate 5490 ** thread. 5491 ** It is intended that this variable be set once 5492 ** as part of process initialization and before any SQLite interface 5493 ** routines have been called and that this variable remain unchanged 5494 ** thereafter. 5495 ** 5496 ** ^The [data_store_directory pragma] may modify this variable and cause 5497 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5498 ** the [data_store_directory pragma] always assumes that any string 5499 ** that this variable points to is held in memory obtained from 5500 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5501 ** using [sqlite3_free]. 5502 ** Hence, if this variable is modified directly, either it should be 5503 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5504 ** or else the use of the [data_store_directory pragma] should be avoided. 5505 */ 5506 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5507 5508 /* 5509 ** CAPI3REF: Test For Auto-Commit Mode 5510 ** KEYWORDS: {autocommit mode} 5511 ** METHOD: sqlite3 5512 ** 5513 ** ^The sqlite3_get_autocommit() interface returns non-zero or 5514 ** zero if the given database connection is or is not in autocommit mode, 5515 ** respectively. ^Autocommit mode is on by default. 5516 ** ^Autocommit mode is disabled by a [BEGIN] statement. 5517 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5518 ** 5519 ** If certain kinds of errors occur on a statement within a multi-statement 5520 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5521 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5522 ** transaction might be rolled back automatically. The only way to 5523 ** find out whether SQLite automatically rolled back the transaction after 5524 ** an error is to use this function. 5525 ** 5526 ** If another thread changes the autocommit status of the database 5527 ** connection while this routine is running, then the return value 5528 ** is undefined. 5529 */ 5530 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 5531 5532 /* 5533 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 5534 ** METHOD: sqlite3_stmt 5535 ** 5536 ** ^The sqlite3_db_handle interface returns the [database connection] handle 5537 ** to which a [prepared statement] belongs. ^The [database connection] 5538 ** returned by sqlite3_db_handle is the same [database connection] 5539 ** that was the first argument 5540 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5541 ** create the statement in the first place. 5542 */ 5543 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5544 5545 /* 5546 ** CAPI3REF: Return The Filename For A Database Connection 5547 ** METHOD: sqlite3 5548 ** 5549 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5550 ** associated with database N of connection D. ^The main database file 5551 ** has the name "main". If there is no attached database N on the database 5552 ** connection D, or if database N is a temporary or in-memory database, then 5553 ** a NULL pointer is returned. 5554 ** 5555 ** ^The filename returned by this function is the output of the 5556 ** xFullPathname method of the [VFS]. ^In other words, the filename 5557 ** will be an absolute pathname, even if the filename used 5558 ** to open the database originally was a URI or relative pathname. 5559 */ 5560 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5561 5562 /* 5563 ** CAPI3REF: Determine if a database is read-only 5564 ** METHOD: sqlite3 5565 ** 5566 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5567 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5568 ** the name of a database on connection D. 5569 */ 5570 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5571 5572 /* 5573 ** CAPI3REF: Find the next prepared statement 5574 ** METHOD: sqlite3 5575 ** 5576 ** ^This interface returns a pointer to the next [prepared statement] after 5577 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5578 ** then this interface returns a pointer to the first prepared statement 5579 ** associated with the database connection pDb. ^If no prepared statement 5580 ** satisfies the conditions of this routine, it returns NULL. 5581 ** 5582 ** The [database connection] pointer D in a call to 5583 ** [sqlite3_next_stmt(D,S)] must refer to an open database 5584 ** connection and in particular must not be a NULL pointer. 5585 */ 5586 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5587 5588 /* 5589 ** CAPI3REF: Commit And Rollback Notification Callbacks 5590 ** METHOD: sqlite3 5591 ** 5592 ** ^The sqlite3_commit_hook() interface registers a callback 5593 ** function to be invoked whenever a transaction is [COMMIT | committed]. 5594 ** ^Any callback set by a previous call to sqlite3_commit_hook() 5595 ** for the same database connection is overridden. 5596 ** ^The sqlite3_rollback_hook() interface registers a callback 5597 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5598 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 5599 ** for the same database connection is overridden. 5600 ** ^The pArg argument is passed through to the callback. 5601 ** ^If the callback on a commit hook function returns non-zero, 5602 ** then the commit is converted into a rollback. 5603 ** 5604 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5605 ** return the P argument from the previous call of the same function 5606 ** on the same [database connection] D, or NULL for 5607 ** the first call for each function on D. 5608 ** 5609 ** The commit and rollback hook callbacks are not reentrant. 5610 ** The callback implementation must not do anything that will modify 5611 ** the database connection that invoked the callback. Any actions 5612 ** to modify the database connection must be deferred until after the 5613 ** completion of the [sqlite3_step()] call that triggered the commit 5614 ** or rollback hook in the first place. 5615 ** Note that running any other SQL statements, including SELECT statements, 5616 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5617 ** the database connections for the meaning of "modify" in this paragraph. 5618 ** 5619 ** ^Registering a NULL function disables the callback. 5620 ** 5621 ** ^When the commit hook callback routine returns zero, the [COMMIT] 5622 ** operation is allowed to continue normally. ^If the commit hook 5623 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5624 ** ^The rollback hook is invoked on a rollback that results from a commit 5625 ** hook returning non-zero, just as it would be with any other rollback. 5626 ** 5627 ** ^For the purposes of this API, a transaction is said to have been 5628 ** rolled back if an explicit "ROLLBACK" statement is executed, or 5629 ** an error or constraint causes an implicit rollback to occur. 5630 ** ^The rollback callback is not invoked if a transaction is 5631 ** automatically rolled back because the database connection is closed. 5632 ** 5633 ** See also the [sqlite3_update_hook()] interface. 5634 */ 5635 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5636 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5637 5638 /* 5639 ** CAPI3REF: Data Change Notification Callbacks 5640 ** METHOD: sqlite3 5641 ** 5642 ** ^The sqlite3_update_hook() interface registers a callback function 5643 ** with the [database connection] identified by the first argument 5644 ** to be invoked whenever a row is updated, inserted or deleted in 5645 ** a [rowid table]. 5646 ** ^Any callback set by a previous call to this function 5647 ** for the same database connection is overridden. 5648 ** 5649 ** ^The second argument is a pointer to the function to invoke when a 5650 ** row is updated, inserted or deleted in a rowid table. 5651 ** ^The first argument to the callback is a copy of the third argument 5652 ** to sqlite3_update_hook(). 5653 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5654 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 5655 ** to be invoked. 5656 ** ^The third and fourth arguments to the callback contain pointers to the 5657 ** database and table name containing the affected row. 5658 ** ^The final callback parameter is the [rowid] of the row. 5659 ** ^In the case of an update, this is the [rowid] after the update takes place. 5660 ** 5661 ** ^(The update hook is not invoked when internal system tables are 5662 ** modified (i.e. sqlite_master and sqlite_sequence).)^ 5663 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5664 ** 5665 ** ^In the current implementation, the update hook 5666 ** is not invoked when conflicting rows are deleted because of an 5667 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5668 ** invoked when rows are deleted using the [truncate optimization]. 5669 ** The exceptions defined in this paragraph might change in a future 5670 ** release of SQLite. 5671 ** 5672 ** The update hook implementation must not do anything that will modify 5673 ** the database connection that invoked the update hook. Any actions 5674 ** to modify the database connection must be deferred until after the 5675 ** completion of the [sqlite3_step()] call that triggered the update hook. 5676 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5677 ** database connections for the meaning of "modify" in this paragraph. 5678 ** 5679 ** ^The sqlite3_update_hook(D,C,P) function 5680 ** returns the P argument from the previous call 5681 ** on the same [database connection] D, or NULL for 5682 ** the first call on D. 5683 ** 5684 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5685 ** and [sqlite3_preupdate_hook()] interfaces. 5686 */ 5687 SQLITE_API void *sqlite3_update_hook( 5688 sqlite3*, 5689 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5690 void* 5691 ); 5692 5693 /* 5694 ** CAPI3REF: Enable Or Disable Shared Pager Cache 5695 ** 5696 ** ^(This routine enables or disables the sharing of the database cache 5697 ** and schema data structures between [database connection | connections] 5698 ** to the same database. Sharing is enabled if the argument is true 5699 ** and disabled if the argument is false.)^ 5700 ** 5701 ** ^Cache sharing is enabled and disabled for an entire process. 5702 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 5703 ** In prior versions of SQLite, 5704 ** sharing was enabled or disabled for each thread separately. 5705 ** 5706 ** ^(The cache sharing mode set by this interface effects all subsequent 5707 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5708 ** Existing database connections continue use the sharing mode 5709 ** that was in effect at the time they were opened.)^ 5710 ** 5711 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5712 ** successfully. An [error code] is returned otherwise.)^ 5713 ** 5714 ** ^Shared cache is disabled by default. But this might change in 5715 ** future releases of SQLite. Applications that care about shared 5716 ** cache setting should set it explicitly. 5717 ** 5718 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5719 ** and will always return SQLITE_MISUSE. On those systems, 5720 ** shared cache mode should be enabled per-database connection via 5721 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5722 ** 5723 ** This interface is threadsafe on processors where writing a 5724 ** 32-bit integer is atomic. 5725 ** 5726 ** See Also: [SQLite Shared-Cache Mode] 5727 */ 5728 SQLITE_API int sqlite3_enable_shared_cache(int); 5729 5730 /* 5731 ** CAPI3REF: Attempt To Free Heap Memory 5732 ** 5733 ** ^The sqlite3_release_memory() interface attempts to free N bytes 5734 ** of heap memory by deallocating non-essential memory allocations 5735 ** held by the database library. Memory used to cache database 5736 ** pages to improve performance is an example of non-essential memory. 5737 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 5738 ** which might be more or less than the amount requested. 5739 ** ^The sqlite3_release_memory() routine is a no-op returning zero 5740 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5741 ** 5742 ** See also: [sqlite3_db_release_memory()] 5743 */ 5744 SQLITE_API int sqlite3_release_memory(int); 5745 5746 /* 5747 ** CAPI3REF: Free Memory Used By A Database Connection 5748 ** METHOD: sqlite3 5749 ** 5750 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5751 ** memory as possible from database connection D. Unlike the 5752 ** [sqlite3_release_memory()] interface, this interface is in effect even 5753 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5754 ** omitted. 5755 ** 5756 ** See also: [sqlite3_release_memory()] 5757 */ 5758 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 5759 5760 /* 5761 ** CAPI3REF: Impose A Limit On Heap Size 5762 ** 5763 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5764 ** soft limit on the amount of heap memory that may be allocated by SQLite. 5765 ** ^SQLite strives to keep heap memory utilization below the soft heap 5766 ** limit by reducing the number of pages held in the page cache 5767 ** as heap memory usages approaches the limit. 5768 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 5769 ** below the limit, it will exceed the limit rather than generate 5770 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5771 ** is advisory only. 5772 ** 5773 ** ^The return value from sqlite3_soft_heap_limit64() is the size of 5774 ** the soft heap limit prior to the call, or negative in the case of an 5775 ** error. ^If the argument N is negative 5776 ** then no change is made to the soft heap limit. Hence, the current 5777 ** size of the soft heap limit can be determined by invoking 5778 ** sqlite3_soft_heap_limit64() with a negative argument. 5779 ** 5780 ** ^If the argument N is zero then the soft heap limit is disabled. 5781 ** 5782 ** ^(The soft heap limit is not enforced in the current implementation 5783 ** if one or more of following conditions are true: 5784 ** 5785 ** <ul> 5786 ** <li> The soft heap limit is set to zero. 5787 ** <li> Memory accounting is disabled using a combination of the 5788 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5789 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5790 ** <li> An alternative page cache implementation is specified using 5791 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5792 ** <li> The page cache allocates from its own memory pool supplied 5793 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5794 ** from the heap. 5795 ** </ul>)^ 5796 ** 5797 ** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 5798 ** the soft heap limit is enforced 5799 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5800 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5801 ** the soft heap limit is enforced on every memory allocation. Without 5802 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5803 ** when memory is allocated by the page cache. Testing suggests that because 5804 ** the page cache is the predominate memory user in SQLite, most 5805 ** applications will achieve adequate soft heap limit enforcement without 5806 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5807 ** 5808 ** The circumstances under which SQLite will enforce the soft heap limit may 5809 ** changes in future releases of SQLite. 5810 */ 5811 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5812 5813 /* 5814 ** CAPI3REF: Deprecated Soft Heap Limit Interface 5815 ** DEPRECATED 5816 ** 5817 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5818 ** interface. This routine is provided for historical compatibility 5819 ** only. All new applications should use the 5820 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 5821 */ 5822 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5823 5824 5825 /* 5826 ** CAPI3REF: Extract Metadata About A Column Of A Table 5827 ** METHOD: sqlite3 5828 ** 5829 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5830 ** information about column C of table T in database D 5831 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5832 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 5833 ** the final five arguments with appropriate values if the specified 5834 ** column exists. ^The sqlite3_table_column_metadata() interface returns 5835 ** SQLITE_ERROR and if the specified column does not exist. 5836 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5837 ** NULL pointer, then this routine simply checks for the existence of the 5838 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5839 ** does not. If the table name parameter T in a call to 5840 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 5841 ** undefined behavior. 5842 ** 5843 ** ^The column is identified by the second, third and fourth parameters to 5844 ** this function. ^(The second parameter is either the name of the database 5845 ** (i.e. "main", "temp", or an attached database) containing the specified 5846 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5847 ** for the table using the same algorithm used by the database engine to 5848 ** resolve unqualified table references. 5849 ** 5850 ** ^The third and fourth parameters to this function are the table and column 5851 ** name of the desired column, respectively. 5852 ** 5853 ** ^Metadata is returned by writing to the memory locations passed as the 5th 5854 ** and subsequent parameters to this function. ^Any of these arguments may be 5855 ** NULL, in which case the corresponding element of metadata is omitted. 5856 ** 5857 ** ^(<blockquote> 5858 ** <table border="1"> 5859 ** <tr><th> Parameter <th> Output<br>Type <th> Description 5860 ** 5861 ** <tr><td> 5th <td> const char* <td> Data type 5862 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5863 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5864 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5865 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5866 ** </table> 5867 ** </blockquote>)^ 5868 ** 5869 ** ^The memory pointed to by the character pointers returned for the 5870 ** declaration type and collation sequence is valid until the next 5871 ** call to any SQLite API function. 5872 ** 5873 ** ^If the specified table is actually a view, an [error code] is returned. 5874 ** 5875 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5876 ** is not a [WITHOUT ROWID] table and an 5877 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5878 ** parameters are set for the explicitly declared column. ^(If there is no 5879 ** [INTEGER PRIMARY KEY] column, then the outputs 5880 ** for the [rowid] are set as follows: 5881 ** 5882 ** <pre> 5883 ** data type: "INTEGER" 5884 ** collation sequence: "BINARY" 5885 ** not null: 0 5886 ** primary key: 1 5887 ** auto increment: 0 5888 ** </pre>)^ 5889 ** 5890 ** ^This function causes all database schemas to be read from disk and 5891 ** parsed, if that has not already been done, and returns an error if 5892 ** any errors are encountered while loading the schema. 5893 */ 5894 SQLITE_API int sqlite3_table_column_metadata( 5895 sqlite3 *db, /* Connection handle */ 5896 const char *zDbName, /* Database name or NULL */ 5897 const char *zTableName, /* Table name */ 5898 const char *zColumnName, /* Column name */ 5899 char const **pzDataType, /* OUTPUT: Declared data type */ 5900 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5901 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5902 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5903 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5904 ); 5905 5906 /* 5907 ** CAPI3REF: Load An Extension 5908 ** METHOD: sqlite3 5909 ** 5910 ** ^This interface loads an SQLite extension library from the named file. 5911 ** 5912 ** ^The sqlite3_load_extension() interface attempts to load an 5913 ** [SQLite extension] library contained in the file zFile. If 5914 ** the file cannot be loaded directly, attempts are made to load 5915 ** with various operating-system specific extensions added. 5916 ** So for example, if "samplelib" cannot be loaded, then names like 5917 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5918 ** be tried also. 5919 ** 5920 ** ^The entry point is zProc. 5921 ** ^(zProc may be 0, in which case SQLite will try to come up with an 5922 ** entry point name on its own. It first tries "sqlite3_extension_init". 5923 ** If that does not work, it constructs a name "sqlite3_X_init" where the 5924 ** X is consists of the lower-case equivalent of all ASCII alphabetic 5925 ** characters in the filename from the last "/" to the first following 5926 ** "." and omitting any initial "lib".)^ 5927 ** ^The sqlite3_load_extension() interface returns 5928 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5929 ** ^If an error occurs and pzErrMsg is not 0, then the 5930 ** [sqlite3_load_extension()] interface shall attempt to 5931 ** fill *pzErrMsg with error message text stored in memory 5932 ** obtained from [sqlite3_malloc()]. The calling function 5933 ** should free this memory by calling [sqlite3_free()]. 5934 ** 5935 ** ^Extension loading must be enabled using 5936 ** [sqlite3_enable_load_extension()] or 5937 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 5938 ** prior to calling this API, 5939 ** otherwise an error will be returned. 5940 ** 5941 ** <b>Security warning:</b> It is recommended that the 5942 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 5943 ** interface. The use of the [sqlite3_enable_load_extension()] interface 5944 ** should be avoided. This will keep the SQL function [load_extension()] 5945 ** disabled and prevent SQL injections from giving attackers 5946 ** access to extension loading capabilities. 5947 ** 5948 ** See also the [load_extension() SQL function]. 5949 */ 5950 SQLITE_API int sqlite3_load_extension( 5951 sqlite3 *db, /* Load the extension into this database connection */ 5952 const char *zFile, /* Name of the shared library containing extension */ 5953 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5954 char **pzErrMsg /* Put error message here if not 0 */ 5955 ); 5956 5957 /* 5958 ** CAPI3REF: Enable Or Disable Extension Loading 5959 ** METHOD: sqlite3 5960 ** 5961 ** ^So as not to open security holes in older applications that are 5962 ** unprepared to deal with [extension loading], and as a means of disabling 5963 ** [extension loading] while evaluating user-entered SQL, the following API 5964 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5965 ** 5966 ** ^Extension loading is off by default. 5967 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5968 ** to turn extension loading on and call it with onoff==0 to turn 5969 ** it back off again. 5970 ** 5971 ** ^This interface enables or disables both the C-API 5972 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 5973 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 5974 ** to enable or disable only the C-API.)^ 5975 ** 5976 ** <b>Security warning:</b> It is recommended that extension loading 5977 ** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 5978 ** rather than this interface, so the [load_extension()] SQL function 5979 ** remains disabled. This will prevent SQL injections from giving attackers 5980 ** access to extension loading capabilities. 5981 */ 5982 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5983 5984 /* 5985 ** CAPI3REF: Automatically Load Statically Linked Extensions 5986 ** 5987 ** ^This interface causes the xEntryPoint() function to be invoked for 5988 ** each new [database connection] that is created. The idea here is that 5989 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5990 ** that is to be automatically loaded into all new database connections. 5991 ** 5992 ** ^(Even though the function prototype shows that xEntryPoint() takes 5993 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 5994 ** arguments and expects an integer result as if the signature of the 5995 ** entry point where as follows: 5996 ** 5997 ** <blockquote><pre> 5998 ** int xEntryPoint( 5999 ** sqlite3 *db, 6000 ** const char **pzErrMsg, 6001 ** const struct sqlite3_api_routines *pThunk 6002 ** ); 6003 ** </pre></blockquote>)^ 6004 ** 6005 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6006 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6007 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6008 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6009 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6010 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6011 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6012 ** 6013 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6014 ** on the list of automatic extensions is a harmless no-op. ^No entry point 6015 ** will be called more than once for each database connection that is opened. 6016 ** 6017 ** See also: [sqlite3_reset_auto_extension()] 6018 ** and [sqlite3_cancel_auto_extension()] 6019 */ 6020 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6021 6022 /* 6023 ** CAPI3REF: Cancel Automatic Extension Loading 6024 ** 6025 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6026 ** initialization routine X that was registered using a prior call to 6027 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6028 ** routine returns 1 if initialization routine X was successfully 6029 ** unregistered and it returns 0 if X was not on the list of initialization 6030 ** routines. 6031 */ 6032 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6033 6034 /* 6035 ** CAPI3REF: Reset Automatic Extension Loading 6036 ** 6037 ** ^This interface disables all automatic extensions previously 6038 ** registered using [sqlite3_auto_extension()]. 6039 */ 6040 SQLITE_API void sqlite3_reset_auto_extension(void); 6041 6042 /* 6043 ** The interface to the virtual-table mechanism is currently considered 6044 ** to be experimental. The interface might change in incompatible ways. 6045 ** If this is a problem for you, do not use the interface at this time. 6046 ** 6047 ** When the virtual-table mechanism stabilizes, we will declare the 6048 ** interface fixed, support it indefinitely, and remove this comment. 6049 */ 6050 6051 /* 6052 ** Structures used by the virtual table interface 6053 */ 6054 typedef struct sqlite3_vtab sqlite3_vtab; 6055 typedef struct sqlite3_index_info sqlite3_index_info; 6056 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6057 typedef struct sqlite3_module sqlite3_module; 6058 6059 /* 6060 ** CAPI3REF: Virtual Table Object 6061 ** KEYWORDS: sqlite3_module {virtual table module} 6062 ** 6063 ** This structure, sometimes called a "virtual table module", 6064 ** defines the implementation of a [virtual tables]. 6065 ** This structure consists mostly of methods for the module. 6066 ** 6067 ** ^A virtual table module is created by filling in a persistent 6068 ** instance of this structure and passing a pointer to that instance 6069 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6070 ** ^The registration remains valid until it is replaced by a different 6071 ** module or until the [database connection] closes. The content 6072 ** of this structure must not change while it is registered with 6073 ** any database connection. 6074 */ 6075 struct sqlite3_module { 6076 int iVersion; 6077 int (*xCreate)(sqlite3*, void *pAux, 6078 int argc, const char *const*argv, 6079 sqlite3_vtab **ppVTab, char**); 6080 int (*xConnect)(sqlite3*, void *pAux, 6081 int argc, const char *const*argv, 6082 sqlite3_vtab **ppVTab, char**); 6083 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6084 int (*xDisconnect)(sqlite3_vtab *pVTab); 6085 int (*xDestroy)(sqlite3_vtab *pVTab); 6086 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6087 int (*xClose)(sqlite3_vtab_cursor*); 6088 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6089 int argc, sqlite3_value **argv); 6090 int (*xNext)(sqlite3_vtab_cursor*); 6091 int (*xEof)(sqlite3_vtab_cursor*); 6092 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6093 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6094 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6095 int (*xBegin)(sqlite3_vtab *pVTab); 6096 int (*xSync)(sqlite3_vtab *pVTab); 6097 int (*xCommit)(sqlite3_vtab *pVTab); 6098 int (*xRollback)(sqlite3_vtab *pVTab); 6099 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6100 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6101 void **ppArg); 6102 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6103 /* The methods above are in version 1 of the sqlite_module object. Those 6104 ** below are for version 2 and greater. */ 6105 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6106 int (*xRelease)(sqlite3_vtab *pVTab, int); 6107 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6108 }; 6109 6110 /* 6111 ** CAPI3REF: Virtual Table Indexing Information 6112 ** KEYWORDS: sqlite3_index_info 6113 ** 6114 ** The sqlite3_index_info structure and its substructures is used as part 6115 ** of the [virtual table] interface to 6116 ** pass information into and receive the reply from the [xBestIndex] 6117 ** method of a [virtual table module]. The fields under **Inputs** are the 6118 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 6119 ** results into the **Outputs** fields. 6120 ** 6121 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 6122 ** 6123 ** <blockquote>column OP expr</blockquote> 6124 ** 6125 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6126 ** stored in aConstraint[].op using one of the 6127 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6128 ** ^(The index of the column is stored in 6129 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6130 ** expr on the right-hand side can be evaluated (and thus the constraint 6131 ** is usable) and false if it cannot.)^ 6132 ** 6133 ** ^The optimizer automatically inverts terms of the form "expr OP column" 6134 ** and makes other simplifications to the WHERE clause in an attempt to 6135 ** get as many WHERE clause terms into the form shown above as possible. 6136 ** ^The aConstraint[] array only reports WHERE clause terms that are 6137 ** relevant to the particular virtual table being queried. 6138 ** 6139 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6140 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 6141 ** 6142 ** The colUsed field indicates which columns of the virtual table may be 6143 ** required by the current scan. Virtual table columns are numbered from 6144 ** zero in the order in which they appear within the CREATE TABLE statement 6145 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6146 ** the corresponding bit is set within the colUsed mask if the column may be 6147 ** required by SQLite. If the table has at least 64 columns and any column 6148 ** to the right of the first 63 is required, then bit 63 of colUsed is also 6149 ** set. In other words, column iCol may be required if the expression 6150 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6151 ** non-zero. 6152 ** 6153 ** The [xBestIndex] method must fill aConstraintUsage[] with information 6154 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 6155 ** the right-hand side of the corresponding aConstraint[] is evaluated 6156 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6157 ** is true, then the constraint is assumed to be fully handled by the 6158 ** virtual table and is not checked again by SQLite.)^ 6159 ** 6160 ** ^The idxNum and idxPtr values are recorded and passed into the 6161 ** [xFilter] method. 6162 ** ^[sqlite3_free()] is used to free idxPtr if and only if 6163 ** needToFreeIdxPtr is true. 6164 ** 6165 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6166 ** the correct order to satisfy the ORDER BY clause so that no separate 6167 ** sorting step is required. 6168 ** 6169 ** ^The estimatedCost value is an estimate of the cost of a particular 6170 ** strategy. A cost of N indicates that the cost of the strategy is similar 6171 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 6172 ** indicates that the expense of the operation is similar to that of a 6173 ** binary search on a unique indexed field of an SQLite table with N rows. 6174 ** 6175 ** ^The estimatedRows value is an estimate of the number of rows that 6176 ** will be returned by the strategy. 6177 ** 6178 ** The xBestIndex method may optionally populate the idxFlags field with a 6179 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6180 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6181 ** assumes that the strategy may visit at most one row. 6182 ** 6183 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6184 ** SQLite also assumes that if a call to the xUpdate() method is made as 6185 ** part of the same statement to delete or update a virtual table row and the 6186 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6187 ** any database changes. In other words, if the xUpdate() returns 6188 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6189 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6190 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6191 ** the xUpdate method are automatically rolled back by SQLite. 6192 ** 6193 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6194 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6195 ** If a virtual table extension is 6196 ** used with an SQLite version earlier than 3.8.2, the results of attempting 6197 ** to read or write the estimatedRows field are undefined (but are likely 6198 ** to included crashing the application). The estimatedRows field should 6199 ** therefore only be used if [sqlite3_libversion_number()] returns a 6200 ** value greater than or equal to 3008002. Similarly, the idxFlags field 6201 ** was added for [version 3.9.0] ([dateof:3.9.0]). 6202 ** It may therefore only be used if 6203 ** sqlite3_libversion_number() returns a value greater than or equal to 6204 ** 3009000. 6205 */ 6206 struct sqlite3_index_info { 6207 /* Inputs */ 6208 int nConstraint; /* Number of entries in aConstraint */ 6209 struct sqlite3_index_constraint { 6210 int iColumn; /* Column constrained. -1 for ROWID */ 6211 unsigned char op; /* Constraint operator */ 6212 unsigned char usable; /* True if this constraint is usable */ 6213 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6214 } *aConstraint; /* Table of WHERE clause constraints */ 6215 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6216 struct sqlite3_index_orderby { 6217 int iColumn; /* Column number */ 6218 unsigned char desc; /* True for DESC. False for ASC. */ 6219 } *aOrderBy; /* The ORDER BY clause */ 6220 /* Outputs */ 6221 struct sqlite3_index_constraint_usage { 6222 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6223 unsigned char omit; /* Do not code a test for this constraint */ 6224 } *aConstraintUsage; 6225 int idxNum; /* Number used to identify the index */ 6226 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6227 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6228 int orderByConsumed; /* True if output is already ordered */ 6229 double estimatedCost; /* Estimated cost of using this index */ 6230 /* Fields below are only available in SQLite 3.8.2 and later */ 6231 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6232 /* Fields below are only available in SQLite 3.9.0 and later */ 6233 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6234 /* Fields below are only available in SQLite 3.10.0 and later */ 6235 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6236 }; 6237 6238 /* 6239 ** CAPI3REF: Virtual Table Scan Flags 6240 */ 6241 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6242 6243 /* 6244 ** CAPI3REF: Virtual Table Constraint Operator Codes 6245 ** 6246 ** These macros defined the allowed values for the 6247 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 6248 ** an operator that is part of a constraint term in the wHERE clause of 6249 ** a query that uses a [virtual table]. 6250 */ 6251 #define SQLITE_INDEX_CONSTRAINT_EQ 2 6252 #define SQLITE_INDEX_CONSTRAINT_GT 4 6253 #define SQLITE_INDEX_CONSTRAINT_LE 8 6254 #define SQLITE_INDEX_CONSTRAINT_LT 16 6255 #define SQLITE_INDEX_CONSTRAINT_GE 32 6256 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 6257 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 6258 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 6259 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6260 #define SQLITE_INDEX_CONSTRAINT_NE 68 6261 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6262 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6263 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6264 #define SQLITE_INDEX_CONSTRAINT_IS 72 6265 6266 /* 6267 ** CAPI3REF: Register A Virtual Table Implementation 6268 ** METHOD: sqlite3 6269 ** 6270 ** ^These routines are used to register a new [virtual table module] name. 6271 ** ^Module names must be registered before 6272 ** creating a new [virtual table] using the module and before using a 6273 ** preexisting [virtual table] for the module. 6274 ** 6275 ** ^The module name is registered on the [database connection] specified 6276 ** by the first parameter. ^The name of the module is given by the 6277 ** second parameter. ^The third parameter is a pointer to 6278 ** the implementation of the [virtual table module]. ^The fourth 6279 ** parameter is an arbitrary client data pointer that is passed through 6280 ** into the [xCreate] and [xConnect] methods of the virtual table module 6281 ** when a new virtual table is be being created or reinitialized. 6282 ** 6283 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6284 ** is a pointer to a destructor for the pClientData. ^SQLite will 6285 ** invoke the destructor function (if it is not NULL) when SQLite 6286 ** no longer needs the pClientData pointer. ^The destructor will also 6287 ** be invoked if the call to sqlite3_create_module_v2() fails. 6288 ** ^The sqlite3_create_module() 6289 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 6290 ** destructor. 6291 */ 6292 SQLITE_API int sqlite3_create_module( 6293 sqlite3 *db, /* SQLite connection to register module with */ 6294 const char *zName, /* Name of the module */ 6295 const sqlite3_module *p, /* Methods for the module */ 6296 void *pClientData /* Client data for xCreate/xConnect */ 6297 ); 6298 SQLITE_API int sqlite3_create_module_v2( 6299 sqlite3 *db, /* SQLite connection to register module with */ 6300 const char *zName, /* Name of the module */ 6301 const sqlite3_module *p, /* Methods for the module */ 6302 void *pClientData, /* Client data for xCreate/xConnect */ 6303 void(*xDestroy)(void*) /* Module destructor function */ 6304 ); 6305 6306 /* 6307 ** CAPI3REF: Virtual Table Instance Object 6308 ** KEYWORDS: sqlite3_vtab 6309 ** 6310 ** Every [virtual table module] implementation uses a subclass 6311 ** of this object to describe a particular instance 6312 ** of the [virtual table]. Each subclass will 6313 ** be tailored to the specific needs of the module implementation. 6314 ** The purpose of this superclass is to define certain fields that are 6315 ** common to all module implementations. 6316 ** 6317 ** ^Virtual tables methods can set an error message by assigning a 6318 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6319 ** take care that any prior string is freed by a call to [sqlite3_free()] 6320 ** prior to assigning a new string to zErrMsg. ^After the error message 6321 ** is delivered up to the client application, the string will be automatically 6322 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6323 */ 6324 struct sqlite3_vtab { 6325 const sqlite3_module *pModule; /* The module for this virtual table */ 6326 int nRef; /* Number of open cursors */ 6327 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6328 /* Virtual table implementations will typically add additional fields */ 6329 }; 6330 6331 /* 6332 ** CAPI3REF: Virtual Table Cursor Object 6333 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6334 ** 6335 ** Every [virtual table module] implementation uses a subclass of the 6336 ** following structure to describe cursors that point into the 6337 ** [virtual table] and are used 6338 ** to loop through the virtual table. Cursors are created using the 6339 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6340 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6341 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6342 ** of the module. Each module implementation will define 6343 ** the content of a cursor structure to suit its own needs. 6344 ** 6345 ** This superclass exists in order to define fields of the cursor that 6346 ** are common to all implementations. 6347 */ 6348 struct sqlite3_vtab_cursor { 6349 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6350 /* Virtual table implementations will typically add additional fields */ 6351 }; 6352 6353 /* 6354 ** CAPI3REF: Declare The Schema Of A Virtual Table 6355 ** 6356 ** ^The [xCreate] and [xConnect] methods of a 6357 ** [virtual table module] call this interface 6358 ** to declare the format (the names and datatypes of the columns) of 6359 ** the virtual tables they implement. 6360 */ 6361 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6362 6363 /* 6364 ** CAPI3REF: Overload A Function For A Virtual Table 6365 ** METHOD: sqlite3 6366 ** 6367 ** ^(Virtual tables can provide alternative implementations of functions 6368 ** using the [xFindFunction] method of the [virtual table module]. 6369 ** But global versions of those functions 6370 ** must exist in order to be overloaded.)^ 6371 ** 6372 ** ^(This API makes sure a global version of a function with a particular 6373 ** name and number of parameters exists. If no such function exists 6374 ** before this API is called, a new function is created.)^ ^The implementation 6375 ** of the new function always causes an exception to be thrown. So 6376 ** the new function is not good for anything by itself. Its only 6377 ** purpose is to be a placeholder function that can be overloaded 6378 ** by a [virtual table]. 6379 */ 6380 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6381 6382 /* 6383 ** The interface to the virtual-table mechanism defined above (back up 6384 ** to a comment remarkably similar to this one) is currently considered 6385 ** to be experimental. The interface might change in incompatible ways. 6386 ** If this is a problem for you, do not use the interface at this time. 6387 ** 6388 ** When the virtual-table mechanism stabilizes, we will declare the 6389 ** interface fixed, support it indefinitely, and remove this comment. 6390 */ 6391 6392 /* 6393 ** CAPI3REF: A Handle To An Open BLOB 6394 ** KEYWORDS: {BLOB handle} {BLOB handles} 6395 ** 6396 ** An instance of this object represents an open BLOB on which 6397 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6398 ** ^Objects of this type are created by [sqlite3_blob_open()] 6399 ** and destroyed by [sqlite3_blob_close()]. 6400 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6401 ** can be used to read or write small subsections of the BLOB. 6402 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6403 */ 6404 typedef struct sqlite3_blob sqlite3_blob; 6405 6406 /* 6407 ** CAPI3REF: Open A BLOB For Incremental I/O 6408 ** METHOD: sqlite3 6409 ** CONSTRUCTOR: sqlite3_blob 6410 ** 6411 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6412 ** in row iRow, column zColumn, table zTable in database zDb; 6413 ** in other words, the same BLOB that would be selected by: 6414 ** 6415 ** <pre> 6416 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6417 ** </pre>)^ 6418 ** 6419 ** ^(Parameter zDb is not the filename that contains the database, but 6420 ** rather the symbolic name of the database. For attached databases, this is 6421 ** the name that appears after the AS keyword in the [ATTACH] statement. 6422 ** For the main database file, the database name is "main". For TEMP 6423 ** tables, the database name is "temp".)^ 6424 ** 6425 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 6426 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 6427 ** read-only access. 6428 ** 6429 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6430 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6431 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6432 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6433 ** on *ppBlob after this function it returns. 6434 ** 6435 ** This function fails with SQLITE_ERROR if any of the following are true: 6436 ** <ul> 6437 ** <li> ^(Database zDb does not exist)^, 6438 ** <li> ^(Table zTable does not exist within database zDb)^, 6439 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6440 ** <li> ^(Column zColumn does not exist)^, 6441 ** <li> ^(Row iRow is not present in the table)^, 6442 ** <li> ^(The specified column of row iRow contains a value that is not 6443 ** a TEXT or BLOB value)^, 6444 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6445 ** constraint and the blob is being opened for read/write access)^, 6446 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6447 ** column zColumn is part of a [child key] definition and the blob is 6448 ** being opened for read/write access)^. 6449 ** </ul> 6450 ** 6451 ** ^Unless it returns SQLITE_MISUSE, this function sets the 6452 ** [database connection] error code and message accessible via 6453 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6454 ** 6455 ** A BLOB referenced by sqlite3_blob_open() may be read using the 6456 ** [sqlite3_blob_read()] interface and modified by using 6457 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 6458 ** different row of the same table using the [sqlite3_blob_reopen()] 6459 ** interface. However, the column, table, or database of a [BLOB handle] 6460 ** cannot be changed after the [BLOB handle] is opened. 6461 ** 6462 ** ^(If the row that a BLOB handle points to is modified by an 6463 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6464 ** then the BLOB handle is marked as "expired". 6465 ** This is true if any column of the row is changed, even a column 6466 ** other than the one the BLOB handle is open on.)^ 6467 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6468 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6469 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 6470 ** rolled back by the expiration of the BLOB. Such changes will eventually 6471 ** commit if the transaction continues to completion.)^ 6472 ** 6473 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6474 ** the opened blob. ^The size of a blob may not be changed by this 6475 ** interface. Use the [UPDATE] SQL command to change the size of a 6476 ** blob. 6477 ** 6478 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6479 ** and the built-in [zeroblob] SQL function may be used to create a 6480 ** zero-filled blob to read or write using the incremental-blob interface. 6481 ** 6482 ** To avoid a resource leak, every open [BLOB handle] should eventually 6483 ** be released by a call to [sqlite3_blob_close()]. 6484 ** 6485 ** See also: [sqlite3_blob_close()], 6486 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 6487 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 6488 */ 6489 SQLITE_API int sqlite3_blob_open( 6490 sqlite3*, 6491 const char *zDb, 6492 const char *zTable, 6493 const char *zColumn, 6494 sqlite3_int64 iRow, 6495 int flags, 6496 sqlite3_blob **ppBlob 6497 ); 6498 6499 /* 6500 ** CAPI3REF: Move a BLOB Handle to a New Row 6501 ** METHOD: sqlite3_blob 6502 ** 6503 ** ^This function is used to move an existing [BLOB handle] so that it points 6504 ** to a different row of the same database table. ^The new row is identified 6505 ** by the rowid value passed as the second argument. Only the row can be 6506 ** changed. ^The database, table and column on which the blob handle is open 6507 ** remain the same. Moving an existing [BLOB handle] to a new row is 6508 ** faster than closing the existing handle and opening a new one. 6509 ** 6510 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6511 ** it must exist and there must be either a blob or text value stored in 6512 ** the nominated column.)^ ^If the new row is not present in the table, or if 6513 ** it does not contain a blob or text value, or if another error occurs, an 6514 ** SQLite error code is returned and the blob handle is considered aborted. 6515 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6516 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6517 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6518 ** always returns zero. 6519 ** 6520 ** ^This function sets the database handle error code and message. 6521 */ 6522 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6523 6524 /* 6525 ** CAPI3REF: Close A BLOB Handle 6526 ** DESTRUCTOR: sqlite3_blob 6527 ** 6528 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6529 ** unconditionally. Even if this routine returns an error code, the 6530 ** handle is still closed.)^ 6531 ** 6532 ** ^If the blob handle being closed was opened for read-write access, and if 6533 ** the database is in auto-commit mode and there are no other open read-write 6534 ** blob handles or active write statements, the current transaction is 6535 ** committed. ^If an error occurs while committing the transaction, an error 6536 ** code is returned and the transaction rolled back. 6537 ** 6538 ** Calling this function with an argument that is not a NULL pointer or an 6539 ** open blob handle results in undefined behaviour. ^Calling this routine 6540 ** with a null pointer (such as would be returned by a failed call to 6541 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6542 ** is passed a valid open blob handle, the values returned by the 6543 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6544 */ 6545 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 6546 6547 /* 6548 ** CAPI3REF: Return The Size Of An Open BLOB 6549 ** METHOD: sqlite3_blob 6550 ** 6551 ** ^Returns the size in bytes of the BLOB accessible via the 6552 ** successfully opened [BLOB handle] in its only argument. ^The 6553 ** incremental blob I/O routines can only read or overwriting existing 6554 ** blob content; they cannot change the size of a blob. 6555 ** 6556 ** This routine only works on a [BLOB handle] which has been created 6557 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6558 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6559 ** to this routine results in undefined and probably undesirable behavior. 6560 */ 6561 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 6562 6563 /* 6564 ** CAPI3REF: Read Data From A BLOB Incrementally 6565 ** METHOD: sqlite3_blob 6566 ** 6567 ** ^(This function is used to read data from an open [BLOB handle] into a 6568 ** caller-supplied buffer. N bytes of data are copied into buffer Z 6569 ** from the open BLOB, starting at offset iOffset.)^ 6570 ** 6571 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6572 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6573 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 6574 ** ^The size of the blob (and hence the maximum value of N+iOffset) 6575 ** can be determined using the [sqlite3_blob_bytes()] interface. 6576 ** 6577 ** ^An attempt to read from an expired [BLOB handle] fails with an 6578 ** error code of [SQLITE_ABORT]. 6579 ** 6580 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6581 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6582 ** 6583 ** This routine only works on a [BLOB handle] which has been created 6584 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6585 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6586 ** to this routine results in undefined and probably undesirable behavior. 6587 ** 6588 ** See also: [sqlite3_blob_write()]. 6589 */ 6590 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6591 6592 /* 6593 ** CAPI3REF: Write Data Into A BLOB Incrementally 6594 ** METHOD: sqlite3_blob 6595 ** 6596 ** ^(This function is used to write data into an open [BLOB handle] from a 6597 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 6598 ** into the open BLOB, starting at offset iOffset.)^ 6599 ** 6600 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6601 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6602 ** ^Unless SQLITE_MISUSE is returned, this function sets the 6603 ** [database connection] error code and message accessible via 6604 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6605 ** 6606 ** ^If the [BLOB handle] passed as the first argument was not opened for 6607 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6608 ** this function returns [SQLITE_READONLY]. 6609 ** 6610 ** This function may only modify the contents of the BLOB; it is 6611 ** not possible to increase the size of a BLOB using this API. 6612 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6613 ** [SQLITE_ERROR] is returned and no data is written. The size of the 6614 ** BLOB (and hence the maximum value of N+iOffset) can be determined 6615 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6616 ** than zero [SQLITE_ERROR] is returned and no data is written. 6617 ** 6618 ** ^An attempt to write to an expired [BLOB handle] fails with an 6619 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6620 ** before the [BLOB handle] expired are not rolled back by the 6621 ** expiration of the handle, though of course those changes might 6622 ** have been overwritten by the statement that expired the BLOB handle 6623 ** or by other independent statements. 6624 ** 6625 ** This routine only works on a [BLOB handle] which has been created 6626 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6627 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6628 ** to this routine results in undefined and probably undesirable behavior. 6629 ** 6630 ** See also: [sqlite3_blob_read()]. 6631 */ 6632 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6633 6634 /* 6635 ** CAPI3REF: Virtual File System Objects 6636 ** 6637 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6638 ** that SQLite uses to interact 6639 ** with the underlying operating system. Most SQLite builds come with a 6640 ** single default VFS that is appropriate for the host computer. 6641 ** New VFSes can be registered and existing VFSes can be unregistered. 6642 ** The following interfaces are provided. 6643 ** 6644 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6645 ** ^Names are case sensitive. 6646 ** ^Names are zero-terminated UTF-8 strings. 6647 ** ^If there is no match, a NULL pointer is returned. 6648 ** ^If zVfsName is NULL then the default VFS is returned. 6649 ** 6650 ** ^New VFSes are registered with sqlite3_vfs_register(). 6651 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6652 ** ^The same VFS can be registered multiple times without injury. 6653 ** ^To make an existing VFS into the default VFS, register it again 6654 ** with the makeDflt flag set. If two different VFSes with the 6655 ** same name are registered, the behavior is undefined. If a 6656 ** VFS is registered with a name that is NULL or an empty string, 6657 ** then the behavior is undefined. 6658 ** 6659 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6660 ** ^(If the default VFS is unregistered, another VFS is chosen as 6661 ** the default. The choice for the new VFS is arbitrary.)^ 6662 */ 6663 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 6664 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6665 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 6666 6667 /* 6668 ** CAPI3REF: Mutexes 6669 ** 6670 ** The SQLite core uses these routines for thread 6671 ** synchronization. Though they are intended for internal 6672 ** use by SQLite, code that links against SQLite is 6673 ** permitted to use any of these routines. 6674 ** 6675 ** The SQLite source code contains multiple implementations 6676 ** of these mutex routines. An appropriate implementation 6677 ** is selected automatically at compile-time. The following 6678 ** implementations are available in the SQLite core: 6679 ** 6680 ** <ul> 6681 ** <li> SQLITE_MUTEX_PTHREADS 6682 ** <li> SQLITE_MUTEX_W32 6683 ** <li> SQLITE_MUTEX_NOOP 6684 ** </ul> 6685 ** 6686 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 6687 ** that does no real locking and is appropriate for use in 6688 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6689 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6690 ** and Windows. 6691 ** 6692 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6693 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6694 ** implementation is included with the library. In this case the 6695 ** application must supply a custom mutex implementation using the 6696 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6697 ** before calling sqlite3_initialize() or any other public sqlite3_ 6698 ** function that calls sqlite3_initialize(). 6699 ** 6700 ** ^The sqlite3_mutex_alloc() routine allocates a new 6701 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6702 ** routine returns NULL if it is unable to allocate the requested 6703 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 6704 ** integer constants: 6705 ** 6706 ** <ul> 6707 ** <li> SQLITE_MUTEX_FAST 6708 ** <li> SQLITE_MUTEX_RECURSIVE 6709 ** <li> SQLITE_MUTEX_STATIC_MASTER 6710 ** <li> SQLITE_MUTEX_STATIC_MEM 6711 ** <li> SQLITE_MUTEX_STATIC_OPEN 6712 ** <li> SQLITE_MUTEX_STATIC_PRNG 6713 ** <li> SQLITE_MUTEX_STATIC_LRU 6714 ** <li> SQLITE_MUTEX_STATIC_PMEM 6715 ** <li> SQLITE_MUTEX_STATIC_APP1 6716 ** <li> SQLITE_MUTEX_STATIC_APP2 6717 ** <li> SQLITE_MUTEX_STATIC_APP3 6718 ** <li> SQLITE_MUTEX_STATIC_VFS1 6719 ** <li> SQLITE_MUTEX_STATIC_VFS2 6720 ** <li> SQLITE_MUTEX_STATIC_VFS3 6721 ** </ul> 6722 ** 6723 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6724 ** cause sqlite3_mutex_alloc() to create 6725 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6726 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6727 ** The mutex implementation does not need to make a distinction 6728 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6729 ** not want to. SQLite will only request a recursive mutex in 6730 ** cases where it really needs one. If a faster non-recursive mutex 6731 ** implementation is available on the host platform, the mutex subsystem 6732 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 6733 ** 6734 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6735 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6736 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 6737 ** used by the current version of SQLite. Future versions of SQLite 6738 ** may add additional static mutexes. Static mutexes are for internal 6739 ** use by SQLite only. Applications that use SQLite mutexes should 6740 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6741 ** SQLITE_MUTEX_RECURSIVE. 6742 ** 6743 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6744 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6745 ** returns a different mutex on every call. ^For the static 6746 ** mutex types, the same mutex is returned on every call that has 6747 ** the same type number. 6748 ** 6749 ** ^The sqlite3_mutex_free() routine deallocates a previously 6750 ** allocated dynamic mutex. Attempting to deallocate a static 6751 ** mutex results in undefined behavior. 6752 ** 6753 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6754 ** to enter a mutex. ^If another thread is already within the mutex, 6755 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6756 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6757 ** upon successful entry. ^(Mutexes created using 6758 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6759 ** In such cases, the 6760 ** mutex must be exited an equal number of times before another thread 6761 ** can enter.)^ If the same thread tries to enter any mutex other 6762 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6763 ** 6764 ** ^(Some systems (for example, Windows 95) do not support the operation 6765 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6766 ** will always return SQLITE_BUSY. The SQLite core only ever uses 6767 ** sqlite3_mutex_try() as an optimization so this is acceptable 6768 ** behavior.)^ 6769 ** 6770 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 6771 ** previously entered by the same thread. The behavior 6772 ** is undefined if the mutex is not currently entered by the 6773 ** calling thread or is not currently allocated. 6774 ** 6775 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6776 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6777 ** behave as no-ops. 6778 ** 6779 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6780 */ 6781 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 6782 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 6783 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 6784 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 6785 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 6786 6787 /* 6788 ** CAPI3REF: Mutex Methods Object 6789 ** 6790 ** An instance of this structure defines the low-level routines 6791 ** used to allocate and use mutexes. 6792 ** 6793 ** Usually, the default mutex implementations provided by SQLite are 6794 ** sufficient, however the application has the option of substituting a custom 6795 ** implementation for specialized deployments or systems for which SQLite 6796 ** does not provide a suitable implementation. In this case, the application 6797 ** creates and populates an instance of this structure to pass 6798 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6799 ** Additionally, an instance of this structure can be used as an 6800 ** output variable when querying the system for the current mutex 6801 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6802 ** 6803 ** ^The xMutexInit method defined by this structure is invoked as 6804 ** part of system initialization by the sqlite3_initialize() function. 6805 ** ^The xMutexInit routine is called by SQLite exactly once for each 6806 ** effective call to [sqlite3_initialize()]. 6807 ** 6808 ** ^The xMutexEnd method defined by this structure is invoked as 6809 ** part of system shutdown by the sqlite3_shutdown() function. The 6810 ** implementation of this method is expected to release all outstanding 6811 ** resources obtained by the mutex methods implementation, especially 6812 ** those obtained by the xMutexInit method. ^The xMutexEnd() 6813 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6814 ** 6815 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6816 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6817 ** xMutexNotheld) implement the following interfaces (respectively): 6818 ** 6819 ** <ul> 6820 ** <li> [sqlite3_mutex_alloc()] </li> 6821 ** <li> [sqlite3_mutex_free()] </li> 6822 ** <li> [sqlite3_mutex_enter()] </li> 6823 ** <li> [sqlite3_mutex_try()] </li> 6824 ** <li> [sqlite3_mutex_leave()] </li> 6825 ** <li> [sqlite3_mutex_held()] </li> 6826 ** <li> [sqlite3_mutex_notheld()] </li> 6827 ** </ul>)^ 6828 ** 6829 ** The only difference is that the public sqlite3_XXX functions enumerated 6830 ** above silently ignore any invocations that pass a NULL pointer instead 6831 ** of a valid mutex handle. The implementations of the methods defined 6832 ** by this structure are not required to handle this case, the results 6833 ** of passing a NULL pointer instead of a valid mutex handle are undefined 6834 ** (i.e. it is acceptable to provide an implementation that segfaults if 6835 ** it is passed a NULL pointer). 6836 ** 6837 ** The xMutexInit() method must be threadsafe. It must be harmless to 6838 ** invoke xMutexInit() multiple times within the same process and without 6839 ** intervening calls to xMutexEnd(). Second and subsequent calls to 6840 ** xMutexInit() must be no-ops. 6841 ** 6842 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6843 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6844 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6845 ** memory allocation for a fast or recursive mutex. 6846 ** 6847 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6848 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6849 ** If xMutexInit fails in any way, it is expected to clean up after itself 6850 ** prior to returning. 6851 */ 6852 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6853 struct sqlite3_mutex_methods { 6854 int (*xMutexInit)(void); 6855 int (*xMutexEnd)(void); 6856 sqlite3_mutex *(*xMutexAlloc)(int); 6857 void (*xMutexFree)(sqlite3_mutex *); 6858 void (*xMutexEnter)(sqlite3_mutex *); 6859 int (*xMutexTry)(sqlite3_mutex *); 6860 void (*xMutexLeave)(sqlite3_mutex *); 6861 int (*xMutexHeld)(sqlite3_mutex *); 6862 int (*xMutexNotheld)(sqlite3_mutex *); 6863 }; 6864 6865 /* 6866 ** CAPI3REF: Mutex Verification Routines 6867 ** 6868 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6869 ** are intended for use inside assert() statements. The SQLite core 6870 ** never uses these routines except inside an assert() and applications 6871 ** are advised to follow the lead of the core. The SQLite core only 6872 ** provides implementations for these routines when it is compiled 6873 ** with the SQLITE_DEBUG flag. External mutex implementations 6874 ** are only required to provide these routines if SQLITE_DEBUG is 6875 ** defined and if NDEBUG is not defined. 6876 ** 6877 ** These routines should return true if the mutex in their argument 6878 ** is held or not held, respectively, by the calling thread. 6879 ** 6880 ** The implementation is not required to provide versions of these 6881 ** routines that actually work. If the implementation does not provide working 6882 ** versions of these routines, it should at least provide stubs that always 6883 ** return true so that one does not get spurious assertion failures. 6884 ** 6885 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 6886 ** the routine should return 1. This seems counter-intuitive since 6887 ** clearly the mutex cannot be held if it does not exist. But 6888 ** the reason the mutex does not exist is because the build is not 6889 ** using mutexes. And we do not want the assert() containing the 6890 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 6891 ** the appropriate thing to do. The sqlite3_mutex_notheld() 6892 ** interface should also return 1 when given a NULL pointer. 6893 */ 6894 #ifndef NDEBUG 6895 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 6896 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 6897 #endif 6898 6899 /* 6900 ** CAPI3REF: Mutex Types 6901 ** 6902 ** The [sqlite3_mutex_alloc()] interface takes a single argument 6903 ** which is one of these integer constants. 6904 ** 6905 ** The set of static mutexes may change from one SQLite release to the 6906 ** next. Applications that override the built-in mutex logic must be 6907 ** prepared to accommodate additional static mutexes. 6908 */ 6909 #define SQLITE_MUTEX_FAST 0 6910 #define SQLITE_MUTEX_RECURSIVE 1 6911 #define SQLITE_MUTEX_STATIC_MASTER 2 6912 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6913 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6914 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6915 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 6916 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6917 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6918 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6919 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6920 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6921 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6922 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 6923 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 6924 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 6925 6926 /* 6927 ** CAPI3REF: Retrieve the mutex for a database connection 6928 ** METHOD: sqlite3 6929 ** 6930 ** ^This interface returns a pointer the [sqlite3_mutex] object that 6931 ** serializes access to the [database connection] given in the argument 6932 ** when the [threading mode] is Serialized. 6933 ** ^If the [threading mode] is Single-thread or Multi-thread then this 6934 ** routine returns a NULL pointer. 6935 */ 6936 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 6937 6938 /* 6939 ** CAPI3REF: Low-Level Control Of Database Files 6940 ** METHOD: sqlite3 6941 ** 6942 ** ^The [sqlite3_file_control()] interface makes a direct call to the 6943 ** xFileControl method for the [sqlite3_io_methods] object associated 6944 ** with a particular database identified by the second argument. ^The 6945 ** name of the database is "main" for the main database or "temp" for the 6946 ** TEMP database, or the name that appears after the AS keyword for 6947 ** databases that are added using the [ATTACH] SQL command. 6948 ** ^A NULL pointer can be used in place of "main" to refer to the 6949 ** main database file. 6950 ** ^The third and fourth parameters to this routine 6951 ** are passed directly through to the second and third parameters of 6952 ** the xFileControl method. ^The return value of the xFileControl 6953 ** method becomes the return value of this routine. 6954 ** 6955 ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6956 ** a pointer to the underlying [sqlite3_file] object to be written into 6957 ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6958 ** case is a short-circuit path which does not actually invoke the 6959 ** underlying sqlite3_io_methods.xFileControl method. 6960 ** 6961 ** ^If the second parameter (zDbName) does not match the name of any 6962 ** open database file, then SQLITE_ERROR is returned. ^This error 6963 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 6964 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 6965 ** also return SQLITE_ERROR. There is no way to distinguish between 6966 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6967 ** xFileControl method. 6968 ** 6969 ** See also: [SQLITE_FCNTL_LOCKSTATE] 6970 */ 6971 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6972 6973 /* 6974 ** CAPI3REF: Testing Interface 6975 ** 6976 ** ^The sqlite3_test_control() interface is used to read out internal 6977 ** state of SQLite and to inject faults into SQLite for testing 6978 ** purposes. ^The first parameter is an operation code that determines 6979 ** the number, meaning, and operation of all subsequent parameters. 6980 ** 6981 ** This interface is not for use by applications. It exists solely 6982 ** for verifying the correct operation of the SQLite library. Depending 6983 ** on how the SQLite library is compiled, this interface might not exist. 6984 ** 6985 ** The details of the operation codes, their meanings, the parameters 6986 ** they take, and what they do are all subject to change without notice. 6987 ** Unlike most of the SQLite API, this function is not guaranteed to 6988 ** operate consistently from one release to the next. 6989 */ 6990 SQLITE_API int sqlite3_test_control(int op, ...); 6991 6992 /* 6993 ** CAPI3REF: Testing Interface Operation Codes 6994 ** 6995 ** These constants are the valid operation code parameters used 6996 ** as the first argument to [sqlite3_test_control()]. 6997 ** 6998 ** These parameters and their meanings are subject to change 6999 ** without notice. These values are for testing purposes only. 7000 ** Applications should not use any of these parameters or the 7001 ** [sqlite3_test_control()] interface. 7002 */ 7003 #define SQLITE_TESTCTRL_FIRST 5 7004 #define SQLITE_TESTCTRL_PRNG_SAVE 5 7005 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 7006 #define SQLITE_TESTCTRL_PRNG_RESET 7 7007 #define SQLITE_TESTCTRL_BITVEC_TEST 8 7008 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 7009 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7010 #define SQLITE_TESTCTRL_PENDING_BYTE 11 7011 #define SQLITE_TESTCTRL_ASSERT 12 7012 #define SQLITE_TESTCTRL_ALWAYS 13 7013 #define SQLITE_TESTCTRL_RESERVE 14 7014 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7015 #define SQLITE_TESTCTRL_ISKEYWORD 16 7016 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7017 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7018 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7019 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7020 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7021 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7022 #define SQLITE_TESTCTRL_BYTEORDER 22 7023 #define SQLITE_TESTCTRL_ISINIT 23 7024 #define SQLITE_TESTCTRL_SORTER_MMAP 24 7025 #define SQLITE_TESTCTRL_IMPOSTER 25 7026 #define SQLITE_TESTCTRL_LAST 25 7027 7028 /* 7029 ** CAPI3REF: SQLite Runtime Status 7030 ** 7031 ** ^These interfaces are used to retrieve runtime status information 7032 ** about the performance of SQLite, and optionally to reset various 7033 ** highwater marks. ^The first argument is an integer code for 7034 ** the specific parameter to measure. ^(Recognized integer codes 7035 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 7036 ** ^The current value of the parameter is returned into *pCurrent. 7037 ** ^The highest recorded value is returned in *pHighwater. ^If the 7038 ** resetFlag is true, then the highest record value is reset after 7039 ** *pHighwater is written. ^(Some parameters do not record the highest 7040 ** value. For those parameters 7041 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7042 ** ^(Other parameters record only the highwater mark and not the current 7043 ** value. For these latter parameters nothing is written into *pCurrent.)^ 7044 ** 7045 ** ^The sqlite3_status() and sqlite3_status64() routines return 7046 ** SQLITE_OK on success and a non-zero [error code] on failure. 7047 ** 7048 ** If either the current value or the highwater mark is too large to 7049 ** be represented by a 32-bit integer, then the values returned by 7050 ** sqlite3_status() are undefined. 7051 ** 7052 ** See also: [sqlite3_db_status()] 7053 */ 7054 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7055 SQLITE_API int sqlite3_status64( 7056 int op, 7057 sqlite3_int64 *pCurrent, 7058 sqlite3_int64 *pHighwater, 7059 int resetFlag 7060 ); 7061 7062 7063 /* 7064 ** CAPI3REF: Status Parameters 7065 ** KEYWORDS: {status parameters} 7066 ** 7067 ** These integer constants designate various run-time status parameters 7068 ** that can be returned by [sqlite3_status()]. 7069 ** 7070 ** <dl> 7071 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7072 ** <dd>This parameter is the current amount of memory checked out 7073 ** using [sqlite3_malloc()], either directly or indirectly. The 7074 ** figure includes calls made to [sqlite3_malloc()] by the application 7075 ** and internal memory usage by the SQLite library. Auxiliary page-cache 7076 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7077 ** this parameter. The amount returned is the sum of the allocation 7078 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7079 ** 7080 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7081 ** <dd>This parameter records the largest memory allocation request 7082 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7083 ** internal equivalents). Only the value returned in the 7084 ** *pHighwater parameter to [sqlite3_status()] is of interest. 7085 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 7086 ** 7087 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7088 ** <dd>This parameter records the number of separate memory allocations 7089 ** currently checked out.</dd>)^ 7090 ** 7091 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7092 ** <dd>This parameter returns the number of pages used out of the 7093 ** [pagecache memory allocator] that was configured using 7094 ** [SQLITE_CONFIG_PAGECACHE]. The 7095 ** value returned is in pages, not in bytes.</dd>)^ 7096 ** 7097 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7098 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7099 ** <dd>This parameter returns the number of bytes of page cache 7100 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7101 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 7102 ** returned value includes allocations that overflowed because they 7103 ** where too large (they were larger than the "sz" parameter to 7104 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7105 ** no space was left in the page cache.</dd>)^ 7106 ** 7107 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7108 ** <dd>This parameter records the largest memory allocation request 7109 ** handed to [pagecache memory allocator]. Only the value returned in the 7110 ** *pHighwater parameter to [sqlite3_status()] is of interest. 7111 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 7112 ** 7113 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7114 ** <dd>No longer used.</dd> 7115 ** 7116 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7117 ** <dd>No longer used.</dd> 7118 ** 7119 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7120 ** <dd>No longer used.</dd> 7121 ** 7122 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7123 ** <dd>The *pHighwater parameter records the deepest parser stack. 7124 ** The *pCurrent value is undefined. The *pHighwater value is only 7125 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7126 ** </dl> 7127 ** 7128 ** New status parameters may be added from time to time. 7129 */ 7130 #define SQLITE_STATUS_MEMORY_USED 0 7131 #define SQLITE_STATUS_PAGECACHE_USED 1 7132 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 7133 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 7134 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 7135 #define SQLITE_STATUS_MALLOC_SIZE 5 7136 #define SQLITE_STATUS_PARSER_STACK 6 7137 #define SQLITE_STATUS_PAGECACHE_SIZE 7 7138 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 7139 #define SQLITE_STATUS_MALLOC_COUNT 9 7140 7141 /* 7142 ** CAPI3REF: Database Connection Status 7143 ** METHOD: sqlite3 7144 ** 7145 ** ^This interface is used to retrieve runtime status information 7146 ** about a single [database connection]. ^The first argument is the 7147 ** database connection object to be interrogated. ^The second argument 7148 ** is an integer constant, taken from the set of 7149 ** [SQLITE_DBSTATUS options], that 7150 ** determines the parameter to interrogate. The set of 7151 ** [SQLITE_DBSTATUS options] is likely 7152 ** to grow in future releases of SQLite. 7153 ** 7154 ** ^The current value of the requested parameter is written into *pCur 7155 ** and the highest instantaneous value is written into *pHiwtr. ^If 7156 ** the resetFlg is true, then the highest instantaneous value is 7157 ** reset back down to the current value. 7158 ** 7159 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 7160 ** non-zero [error code] on failure. 7161 ** 7162 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 7163 */ 7164 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 7165 7166 /* 7167 ** CAPI3REF: Status Parameters for database connections 7168 ** KEYWORDS: {SQLITE_DBSTATUS options} 7169 ** 7170 ** These constants are the available integer "verbs" that can be passed as 7171 ** the second argument to the [sqlite3_db_status()] interface. 7172 ** 7173 ** New verbs may be added in future releases of SQLite. Existing verbs 7174 ** might be discontinued. Applications should check the return code from 7175 ** [sqlite3_db_status()] to make sure that the call worked. 7176 ** The [sqlite3_db_status()] interface will return a non-zero error code 7177 ** if a discontinued or unsupported verb is invoked. 7178 ** 7179 ** <dl> 7180 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 7181 ** <dd>This parameter returns the number of lookaside memory slots currently 7182 ** checked out.</dd>)^ 7183 ** 7184 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 7185 ** <dd>This parameter returns the number malloc attempts that were 7186 ** satisfied using lookaside memory. Only the high-water value is meaningful; 7187 ** the current value is always zero.)^ 7188 ** 7189 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 7190 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 7191 ** <dd>This parameter returns the number malloc attempts that might have 7192 ** been satisfied using lookaside memory but failed due to the amount of 7193 ** memory requested being larger than the lookaside slot size. 7194 ** Only the high-water value is meaningful; 7195 ** the current value is always zero.)^ 7196 ** 7197 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 7198 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 7199 ** <dd>This parameter returns the number malloc attempts that might have 7200 ** been satisfied using lookaside memory but failed due to all lookaside 7201 ** memory already being in use. 7202 ** Only the high-water value is meaningful; 7203 ** the current value is always zero.)^ 7204 ** 7205 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 7206 ** <dd>This parameter returns the approximate number of bytes of heap 7207 ** memory used by all pager caches associated with the database connection.)^ 7208 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 7209 ** 7210 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 7211 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 7212 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 7213 ** pager cache is shared between two or more connections the bytes of heap 7214 ** memory used by that pager cache is divided evenly between the attached 7215 ** connections.)^ In other words, if none of the pager caches associated 7216 ** with the database connection are shared, this request returns the same 7217 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 7218 ** shared, the value returned by this call will be smaller than that returned 7219 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 7220 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 7221 ** 7222 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 7223 ** <dd>This parameter returns the approximate number of bytes of heap 7224 ** memory used to store the schema for all databases associated 7225 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 7226 ** ^The full amount of memory used by the schemas is reported, even if the 7227 ** schema memory is shared with other database connections due to 7228 ** [shared cache mode] being enabled. 7229 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 7230 ** 7231 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 7232 ** <dd>This parameter returns the approximate number of bytes of heap 7233 ** and lookaside memory used by all prepared statements associated with 7234 ** the database connection.)^ 7235 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 7236 ** </dd> 7237 ** 7238 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 7239 ** <dd>This parameter returns the number of pager cache hits that have 7240 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 7241 ** is always 0. 7242 ** </dd> 7243 ** 7244 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 7245 ** <dd>This parameter returns the number of pager cache misses that have 7246 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7247 ** is always 0. 7248 ** </dd> 7249 ** 7250 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7251 ** <dd>This parameter returns the number of dirty cache entries that have 7252 ** been written to disk. Specifically, the number of pages written to the 7253 ** wal file in wal mode databases, or the number of pages written to the 7254 ** database file in rollback mode databases. Any pages written as part of 7255 ** transaction rollback or database recovery operations are not included. 7256 ** If an IO or other error occurs while writing a page to disk, the effect 7257 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7258 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7259 ** </dd> 7260 ** 7261 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7262 ** <dd>This parameter returns zero for the current value if and only if 7263 ** all foreign key constraints (deferred or immediate) have been 7264 ** resolved.)^ ^The highwater mark is always 0. 7265 ** </dd> 7266 ** </dl> 7267 */ 7268 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7269 #define SQLITE_DBSTATUS_CACHE_USED 1 7270 #define SQLITE_DBSTATUS_SCHEMA_USED 2 7271 #define SQLITE_DBSTATUS_STMT_USED 3 7272 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7273 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7274 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7275 #define SQLITE_DBSTATUS_CACHE_HIT 7 7276 #define SQLITE_DBSTATUS_CACHE_MISS 8 7277 #define SQLITE_DBSTATUS_CACHE_WRITE 9 7278 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 7279 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7280 #define SQLITE_DBSTATUS_MAX 11 /* Largest defined DBSTATUS */ 7281 7282 7283 /* 7284 ** CAPI3REF: Prepared Statement Status 7285 ** METHOD: sqlite3_stmt 7286 ** 7287 ** ^(Each prepared statement maintains various 7288 ** [SQLITE_STMTSTATUS counters] that measure the number 7289 ** of times it has performed specific operations.)^ These counters can 7290 ** be used to monitor the performance characteristics of the prepared 7291 ** statements. For example, if the number of table steps greatly exceeds 7292 ** the number of table searches or result rows, that would tend to indicate 7293 ** that the prepared statement is using a full table scan rather than 7294 ** an index. 7295 ** 7296 ** ^(This interface is used to retrieve and reset counter values from 7297 ** a [prepared statement]. The first argument is the prepared statement 7298 ** object to be interrogated. The second argument 7299 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7300 ** to be interrogated.)^ 7301 ** ^The current value of the requested counter is returned. 7302 ** ^If the resetFlg is true, then the counter is reset to zero after this 7303 ** interface call returns. 7304 ** 7305 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7306 */ 7307 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7308 7309 /* 7310 ** CAPI3REF: Status Parameters for prepared statements 7311 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7312 ** 7313 ** These preprocessor macros define integer codes that name counter 7314 ** values associated with the [sqlite3_stmt_status()] interface. 7315 ** The meanings of the various counters are as follows: 7316 ** 7317 ** <dl> 7318 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7319 ** <dd>^This is the number of times that SQLite has stepped forward in 7320 ** a table as part of a full table scan. Large numbers for this counter 7321 ** may indicate opportunities for performance improvement through 7322 ** careful use of indices.</dd> 7323 ** 7324 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7325 ** <dd>^This is the number of sort operations that have occurred. 7326 ** A non-zero value in this counter may indicate an opportunity to 7327 ** improvement performance through careful use of indices.</dd> 7328 ** 7329 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7330 ** <dd>^This is the number of rows inserted into transient indices that 7331 ** were created automatically in order to help joins run faster. 7332 ** A non-zero value in this counter may indicate an opportunity to 7333 ** improvement performance by adding permanent indices that do not 7334 ** need to be reinitialized each time the statement is run.</dd> 7335 ** 7336 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7337 ** <dd>^This is the number of virtual machine operations executed 7338 ** by the prepared statement if that number is less than or equal 7339 ** to 2147483647. The number of virtual machine operations can be 7340 ** used as a proxy for the total work done by the prepared statement. 7341 ** If the number of virtual machine operations exceeds 2147483647 7342 ** then the value returned by this statement status code is undefined. 7343 ** 7344 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 7345 ** <dd>^This is the number of times that the prepare statement has been 7346 ** automatically regenerated due to schema changes or change to 7347 ** [bound parameters] that might affect the query plan. 7348 ** 7349 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 7350 ** <dd>^This is the number of times that the prepared statement has 7351 ** been run. A single "run" for the purposes of this counter is one 7352 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 7353 ** The counter is incremented on the first [sqlite3_step()] call of each 7354 ** cycle. 7355 ** 7356 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 7357 ** <dd>^This is the approximate number of bytes of heap memory 7358 ** used to store the prepared statement. ^This value is not actually 7359 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 7360 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 7361 ** </dd> 7362 ** </dl> 7363 */ 7364 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7365 #define SQLITE_STMTSTATUS_SORT 2 7366 #define SQLITE_STMTSTATUS_AUTOINDEX 3 7367 #define SQLITE_STMTSTATUS_VM_STEP 4 7368 #define SQLITE_STMTSTATUS_REPREPARE 5 7369 #define SQLITE_STMTSTATUS_RUN 6 7370 #define SQLITE_STMTSTATUS_MEMUSED 99 7371 7372 /* 7373 ** CAPI3REF: Custom Page Cache Object 7374 ** 7375 ** The sqlite3_pcache type is opaque. It is implemented by 7376 ** the pluggable module. The SQLite core has no knowledge of 7377 ** its size or internal structure and never deals with the 7378 ** sqlite3_pcache object except by holding and passing pointers 7379 ** to the object. 7380 ** 7381 ** See [sqlite3_pcache_methods2] for additional information. 7382 */ 7383 typedef struct sqlite3_pcache sqlite3_pcache; 7384 7385 /* 7386 ** CAPI3REF: Custom Page Cache Object 7387 ** 7388 ** The sqlite3_pcache_page object represents a single page in the 7389 ** page cache. The page cache will allocate instances of this 7390 ** object. Various methods of the page cache use pointers to instances 7391 ** of this object as parameters or as their return value. 7392 ** 7393 ** See [sqlite3_pcache_methods2] for additional information. 7394 */ 7395 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7396 struct sqlite3_pcache_page { 7397 void *pBuf; /* The content of the page */ 7398 void *pExtra; /* Extra information associated with the page */ 7399 }; 7400 7401 /* 7402 ** CAPI3REF: Application Defined Page Cache. 7403 ** KEYWORDS: {page cache} 7404 ** 7405 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7406 ** register an alternative page cache implementation by passing in an 7407 ** instance of the sqlite3_pcache_methods2 structure.)^ 7408 ** In many applications, most of the heap memory allocated by 7409 ** SQLite is used for the page cache. 7410 ** By implementing a 7411 ** custom page cache using this API, an application can better control 7412 ** the amount of memory consumed by SQLite, the way in which 7413 ** that memory is allocated and released, and the policies used to 7414 ** determine exactly which parts of a database file are cached and for 7415 ** how long. 7416 ** 7417 ** The alternative page cache mechanism is an 7418 ** extreme measure that is only needed by the most demanding applications. 7419 ** The built-in page cache is recommended for most uses. 7420 ** 7421 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7422 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7423 ** the application may discard the parameter after the call to 7424 ** [sqlite3_config()] returns.)^ 7425 ** 7426 ** [[the xInit() page cache method]] 7427 ** ^(The xInit() method is called once for each effective 7428 ** call to [sqlite3_initialize()])^ 7429 ** (usually only once during the lifetime of the process). ^(The xInit() 7430 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7431 ** The intent of the xInit() method is to set up global data structures 7432 ** required by the custom page cache implementation. 7433 ** ^(If the xInit() method is NULL, then the 7434 ** built-in default page cache is used instead of the application defined 7435 ** page cache.)^ 7436 ** 7437 ** [[the xShutdown() page cache method]] 7438 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7439 ** It can be used to clean up 7440 ** any outstanding resources before process shutdown, if required. 7441 ** ^The xShutdown() method may be NULL. 7442 ** 7443 ** ^SQLite automatically serializes calls to the xInit method, 7444 ** so the xInit method need not be threadsafe. ^The 7445 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 7446 ** not need to be threadsafe either. All other methods must be threadsafe 7447 ** in multithreaded applications. 7448 ** 7449 ** ^SQLite will never invoke xInit() more than once without an intervening 7450 ** call to xShutdown(). 7451 ** 7452 ** [[the xCreate() page cache methods]] 7453 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 7454 ** SQLite will typically create one cache instance for each open database file, 7455 ** though this is not guaranteed. ^The 7456 ** first parameter, szPage, is the size in bytes of the pages that must 7457 ** be allocated by the cache. ^szPage will always a power of two. ^The 7458 ** second parameter szExtra is a number of bytes of extra storage 7459 ** associated with each page cache entry. ^The szExtra parameter will 7460 ** a number less than 250. SQLite will use the 7461 ** extra szExtra bytes on each page to store metadata about the underlying 7462 ** database page on disk. The value passed into szExtra depends 7463 ** on the SQLite version, the target platform, and how SQLite was compiled. 7464 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7465 ** created will be used to cache database pages of a file stored on disk, or 7466 ** false if it is used for an in-memory database. The cache implementation 7467 ** does not have to do anything special based with the value of bPurgeable; 7468 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7469 ** never invoke xUnpin() except to deliberately delete a page. 7470 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7471 ** false will always have the "discard" flag set to true. 7472 ** ^Hence, a cache created with bPurgeable false will 7473 ** never contain any unpinned pages. 7474 ** 7475 ** [[the xCachesize() page cache method]] 7476 ** ^(The xCachesize() method may be called at any time by SQLite to set the 7477 ** suggested maximum cache-size (number of pages stored by) the cache 7478 ** instance passed as the first argument. This is the value configured using 7479 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7480 ** parameter, the implementation is not required to do anything with this 7481 ** value; it is advisory only. 7482 ** 7483 ** [[the xPagecount() page cache methods]] 7484 ** The xPagecount() method must return the number of pages currently 7485 ** stored in the cache, both pinned and unpinned. 7486 ** 7487 ** [[the xFetch() page cache methods]] 7488 ** The xFetch() method locates a page in the cache and returns a pointer to 7489 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7490 ** The pBuf element of the returned sqlite3_pcache_page object will be a 7491 ** pointer to a buffer of szPage bytes used to store the content of a 7492 ** single database page. The pExtra element of sqlite3_pcache_page will be 7493 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 7494 ** for each entry in the page cache. 7495 ** 7496 ** The page to be fetched is determined by the key. ^The minimum key value 7497 ** is 1. After it has been retrieved using xFetch, the page is considered 7498 ** to be "pinned". 7499 ** 7500 ** If the requested page is already in the page cache, then the page cache 7501 ** implementation must return a pointer to the page buffer with its content 7502 ** intact. If the requested page is not already in the cache, then the 7503 ** cache implementation should use the value of the createFlag 7504 ** parameter to help it determined what action to take: 7505 ** 7506 ** <table border=1 width=85% align=center> 7507 ** <tr><th> createFlag <th> Behavior when page is not already in cache 7508 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7509 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7510 ** Otherwise return NULL. 7511 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 7512 ** NULL if allocating a new page is effectively impossible. 7513 ** </table> 7514 ** 7515 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7516 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 7517 ** failed.)^ In between the to xFetch() calls, SQLite may 7518 ** attempt to unpin one or more cache pages by spilling the content of 7519 ** pinned pages to disk and synching the operating system disk cache. 7520 ** 7521 ** [[the xUnpin() page cache method]] 7522 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7523 ** as its second argument. If the third parameter, discard, is non-zero, 7524 ** then the page must be evicted from the cache. 7525 ** ^If the discard parameter is 7526 ** zero, then the page may be discarded or retained at the discretion of 7527 ** page cache implementation. ^The page cache implementation 7528 ** may choose to evict unpinned pages at any time. 7529 ** 7530 ** The cache must not perform any reference counting. A single 7531 ** call to xUnpin() unpins the page regardless of the number of prior calls 7532 ** to xFetch(). 7533 ** 7534 ** [[the xRekey() page cache methods]] 7535 ** The xRekey() method is used to change the key value associated with the 7536 ** page passed as the second argument. If the cache 7537 ** previously contains an entry associated with newKey, it must be 7538 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7539 ** to be pinned. 7540 ** 7541 ** When SQLite calls the xTruncate() method, the cache must discard all 7542 ** existing cache entries with page numbers (keys) greater than or equal 7543 ** to the value of the iLimit parameter passed to xTruncate(). If any 7544 ** of these pages are pinned, they are implicitly unpinned, meaning that 7545 ** they can be safely discarded. 7546 ** 7547 ** [[the xDestroy() page cache method]] 7548 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7549 ** All resources associated with the specified cache should be freed. ^After 7550 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7551 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7552 ** functions. 7553 ** 7554 ** [[the xShrink() page cache method]] 7555 ** ^SQLite invokes the xShrink() method when it wants the page cache to 7556 ** free up as much of heap memory as possible. The page cache implementation 7557 ** is not obligated to free any memory, but well-behaved implementations should 7558 ** do their best. 7559 */ 7560 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7561 struct sqlite3_pcache_methods2 { 7562 int iVersion; 7563 void *pArg; 7564 int (*xInit)(void*); 7565 void (*xShutdown)(void*); 7566 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7567 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7568 int (*xPagecount)(sqlite3_pcache*); 7569 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7570 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7571 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7572 unsigned oldKey, unsigned newKey); 7573 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7574 void (*xDestroy)(sqlite3_pcache*); 7575 void (*xShrink)(sqlite3_pcache*); 7576 }; 7577 7578 /* 7579 ** This is the obsolete pcache_methods object that has now been replaced 7580 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7581 ** retained in the header file for backwards compatibility only. 7582 */ 7583 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7584 struct sqlite3_pcache_methods { 7585 void *pArg; 7586 int (*xInit)(void*); 7587 void (*xShutdown)(void*); 7588 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 7589 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7590 int (*xPagecount)(sqlite3_pcache*); 7591 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7592 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 7593 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 7594 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7595 void (*xDestroy)(sqlite3_pcache*); 7596 }; 7597 7598 7599 /* 7600 ** CAPI3REF: Online Backup Object 7601 ** 7602 ** The sqlite3_backup object records state information about an ongoing 7603 ** online backup operation. ^The sqlite3_backup object is created by 7604 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 7605 ** [sqlite3_backup_finish()]. 7606 ** 7607 ** See Also: [Using the SQLite Online Backup API] 7608 */ 7609 typedef struct sqlite3_backup sqlite3_backup; 7610 7611 /* 7612 ** CAPI3REF: Online Backup API. 7613 ** 7614 ** The backup API copies the content of one database into another. 7615 ** It is useful either for creating backups of databases or 7616 ** for copying in-memory databases to or from persistent files. 7617 ** 7618 ** See Also: [Using the SQLite Online Backup API] 7619 ** 7620 ** ^SQLite holds a write transaction open on the destination database file 7621 ** for the duration of the backup operation. 7622 ** ^The source database is read-locked only while it is being read; 7623 ** it is not locked continuously for the entire backup operation. 7624 ** ^Thus, the backup may be performed on a live source database without 7625 ** preventing other database connections from 7626 ** reading or writing to the source database while the backup is underway. 7627 ** 7628 ** ^(To perform a backup operation: 7629 ** <ol> 7630 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 7631 ** backup, 7632 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 7633 ** the data between the two databases, and finally 7634 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 7635 ** associated with the backup operation. 7636 ** </ol>)^ 7637 ** There should be exactly one call to sqlite3_backup_finish() for each 7638 ** successful call to sqlite3_backup_init(). 7639 ** 7640 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 7641 ** 7642 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 7643 ** [database connection] associated with the destination database 7644 ** and the database name, respectively. 7645 ** ^The database name is "main" for the main database, "temp" for the 7646 ** temporary database, or the name specified after the AS keyword in 7647 ** an [ATTACH] statement for an attached database. 7648 ** ^The S and M arguments passed to 7649 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 7650 ** and database name of the source database, respectively. 7651 ** ^The source and destination [database connections] (parameters S and D) 7652 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 7653 ** an error. 7654 ** 7655 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 7656 ** there is already a read or read-write transaction open on the 7657 ** destination database. 7658 ** 7659 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 7660 ** returned and an error code and error message are stored in the 7661 ** destination [database connection] D. 7662 ** ^The error code and message for the failed call to sqlite3_backup_init() 7663 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 7664 ** [sqlite3_errmsg16()] functions. 7665 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 7666 ** [sqlite3_backup] object. 7667 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 7668 ** sqlite3_backup_finish() functions to perform the specified backup 7669 ** operation. 7670 ** 7671 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 7672 ** 7673 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7674 ** the source and destination databases specified by [sqlite3_backup] object B. 7675 ** ^If N is negative, all remaining source pages are copied. 7676 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7677 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 7678 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7679 ** from source to destination, then it returns [SQLITE_DONE]. 7680 ** ^If an error occurs while running sqlite3_backup_step(B,N), 7681 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 7682 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7683 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7684 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7685 ** 7686 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7687 ** <ol> 7688 ** <li> the destination database was opened read-only, or 7689 ** <li> the destination database is using write-ahead-log journaling 7690 ** and the destination and source page sizes differ, or 7691 ** <li> the destination database is an in-memory database and the 7692 ** destination and source page sizes differ. 7693 ** </ol>)^ 7694 ** 7695 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7696 ** the [sqlite3_busy_handler | busy-handler function] 7697 ** is invoked (if one is specified). ^If the 7698 ** busy-handler returns non-zero before the lock is available, then 7699 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 7700 ** sqlite3_backup_step() can be retried later. ^If the source 7701 ** [database connection] 7702 ** is being used to write to the source database when sqlite3_backup_step() 7703 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 7704 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 7705 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 7706 ** [SQLITE_READONLY] is returned, then 7707 ** there is no point in retrying the call to sqlite3_backup_step(). These 7708 ** errors are considered fatal.)^ The application must accept 7709 ** that the backup operation has failed and pass the backup operation handle 7710 ** to the sqlite3_backup_finish() to release associated resources. 7711 ** 7712 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 7713 ** on the destination file. ^The exclusive lock is not released until either 7714 ** sqlite3_backup_finish() is called or the backup operation is complete 7715 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 7716 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 7717 ** lasts for the duration of the sqlite3_backup_step() call. 7718 ** ^Because the source database is not locked between calls to 7719 ** sqlite3_backup_step(), the source database may be modified mid-way 7720 ** through the backup process. ^If the source database is modified by an 7721 ** external process or via a database connection other than the one being 7722 ** used by the backup operation, then the backup will be automatically 7723 ** restarted by the next call to sqlite3_backup_step(). ^If the source 7724 ** database is modified by the using the same database connection as is used 7725 ** by the backup operation, then the backup database is automatically 7726 ** updated at the same time. 7727 ** 7728 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 7729 ** 7730 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 7731 ** application wishes to abandon the backup operation, the application 7732 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 7733 ** ^The sqlite3_backup_finish() interfaces releases all 7734 ** resources associated with the [sqlite3_backup] object. 7735 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 7736 ** active write-transaction on the destination database is rolled back. 7737 ** The [sqlite3_backup] object is invalid 7738 ** and may not be used following a call to sqlite3_backup_finish(). 7739 ** 7740 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 7741 ** sqlite3_backup_step() errors occurred, regardless or whether or not 7742 ** sqlite3_backup_step() completed. 7743 ** ^If an out-of-memory condition or IO error occurred during any prior 7744 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 7745 ** sqlite3_backup_finish() returns the corresponding [error code]. 7746 ** 7747 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7748 ** is not a permanent error and does not affect the return value of 7749 ** sqlite3_backup_finish(). 7750 ** 7751 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7752 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7753 ** 7754 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 7755 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7756 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7757 ** in the source database at the conclusion of the most recent 7758 ** sqlite3_backup_step(). 7759 ** ^(The values returned by these functions are only updated by 7760 ** sqlite3_backup_step(). If the source database is modified in a way that 7761 ** changes the size of the source database or the number of pages remaining, 7762 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 7763 ** and sqlite3_backup_remaining() until after the next 7764 ** sqlite3_backup_step().)^ 7765 ** 7766 ** <b>Concurrent Usage of Database Handles</b> 7767 ** 7768 ** ^The source [database connection] may be used by the application for other 7769 ** purposes while a backup operation is underway or being initialized. 7770 ** ^If SQLite is compiled and configured to support threadsafe database 7771 ** connections, then the source database connection may be used concurrently 7772 ** from within other threads. 7773 ** 7774 ** However, the application must guarantee that the destination 7775 ** [database connection] is not passed to any other API (by any thread) after 7776 ** sqlite3_backup_init() is called and before the corresponding call to 7777 ** sqlite3_backup_finish(). SQLite does not currently check to see 7778 ** if the application incorrectly accesses the destination [database connection] 7779 ** and so no error code is reported, but the operations may malfunction 7780 ** nevertheless. Use of the destination database connection while a 7781 ** backup is in progress might also also cause a mutex deadlock. 7782 ** 7783 ** If running in [shared cache mode], the application must 7784 ** guarantee that the shared cache used by the destination database 7785 ** is not accessed while the backup is running. In practice this means 7786 ** that the application must guarantee that the disk file being 7787 ** backed up to is not accessed by any connection within the process, 7788 ** not just the specific connection that was passed to sqlite3_backup_init(). 7789 ** 7790 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7791 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7792 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7793 ** APIs are not strictly speaking threadsafe. If they are invoked at the 7794 ** same time as another thread is invoking sqlite3_backup_step() it is 7795 ** possible that they return invalid values. 7796 */ 7797 SQLITE_API sqlite3_backup *sqlite3_backup_init( 7798 sqlite3 *pDest, /* Destination database handle */ 7799 const char *zDestName, /* Destination database name */ 7800 sqlite3 *pSource, /* Source database handle */ 7801 const char *zSourceName /* Source database name */ 7802 ); 7803 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 7804 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 7805 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 7806 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 7807 7808 /* 7809 ** CAPI3REF: Unlock Notification 7810 ** METHOD: sqlite3 7811 ** 7812 ** ^When running in shared-cache mode, a database operation may fail with 7813 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7814 ** individual tables within the shared-cache cannot be obtained. See 7815 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7816 ** ^This API may be used to register a callback that SQLite will invoke 7817 ** when the connection currently holding the required lock relinquishes it. 7818 ** ^This API is only available if the library was compiled with the 7819 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7820 ** 7821 ** See Also: [Using the SQLite Unlock Notification Feature]. 7822 ** 7823 ** ^Shared-cache locks are released when a database connection concludes 7824 ** its current transaction, either by committing it or rolling it back. 7825 ** 7826 ** ^When a connection (known as the blocked connection) fails to obtain a 7827 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7828 ** identity of the database connection (the blocking connection) that 7829 ** has locked the required resource is stored internally. ^After an 7830 ** application receives an SQLITE_LOCKED error, it may call the 7831 ** sqlite3_unlock_notify() method with the blocked connection handle as 7832 ** the first argument to register for a callback that will be invoked 7833 ** when the blocking connections current transaction is concluded. ^The 7834 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7835 ** call that concludes the blocking connections transaction. 7836 ** 7837 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7838 ** there is a chance that the blocking connection will have already 7839 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7840 ** If this happens, then the specified callback is invoked immediately, 7841 ** from within the call to sqlite3_unlock_notify().)^ 7842 ** 7843 ** ^If the blocked connection is attempting to obtain a write-lock on a 7844 ** shared-cache table, and more than one other connection currently holds 7845 ** a read-lock on the same table, then SQLite arbitrarily selects one of 7846 ** the other connections to use as the blocking connection. 7847 ** 7848 ** ^(There may be at most one unlock-notify callback registered by a 7849 ** blocked connection. If sqlite3_unlock_notify() is called when the 7850 ** blocked connection already has a registered unlock-notify callback, 7851 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7852 ** called with a NULL pointer as its second argument, then any existing 7853 ** unlock-notify callback is canceled. ^The blocked connections 7854 ** unlock-notify callback may also be canceled by closing the blocked 7855 ** connection using [sqlite3_close()]. 7856 ** 7857 ** The unlock-notify callback is not reentrant. If an application invokes 7858 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 7859 ** crash or deadlock may be the result. 7860 ** 7861 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7862 ** returns SQLITE_OK. 7863 ** 7864 ** <b>Callback Invocation Details</b> 7865 ** 7866 ** When an unlock-notify callback is registered, the application provides a 7867 ** single void* pointer that is passed to the callback when it is invoked. 7868 ** However, the signature of the callback function allows SQLite to pass 7869 ** it an array of void* context pointers. The first argument passed to 7870 ** an unlock-notify callback is a pointer to an array of void* pointers, 7871 ** and the second is the number of entries in the array. 7872 ** 7873 ** When a blocking connections transaction is concluded, there may be 7874 ** more than one blocked connection that has registered for an unlock-notify 7875 ** callback. ^If two or more such blocked connections have specified the 7876 ** same callback function, then instead of invoking the callback function 7877 ** multiple times, it is invoked once with the set of void* context pointers 7878 ** specified by the blocked connections bundled together into an array. 7879 ** This gives the application an opportunity to prioritize any actions 7880 ** related to the set of unblocked database connections. 7881 ** 7882 ** <b>Deadlock Detection</b> 7883 ** 7884 ** Assuming that after registering for an unlock-notify callback a 7885 ** database waits for the callback to be issued before taking any further 7886 ** action (a reasonable assumption), then using this API may cause the 7887 ** application to deadlock. For example, if connection X is waiting for 7888 ** connection Y's transaction to be concluded, and similarly connection 7889 ** Y is waiting on connection X's transaction, then neither connection 7890 ** will proceed and the system may remain deadlocked indefinitely. 7891 ** 7892 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7893 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 7894 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7895 ** unlock-notify callback is registered. The system is said to be in 7896 ** a deadlocked state if connection A has registered for an unlock-notify 7897 ** callback on the conclusion of connection B's transaction, and connection 7898 ** B has itself registered for an unlock-notify callback when connection 7899 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 7900 ** the system is also considered to be deadlocked if connection B has 7901 ** registered for an unlock-notify callback on the conclusion of connection 7902 ** C's transaction, where connection C is waiting on connection A. ^Any 7903 ** number of levels of indirection are allowed. 7904 ** 7905 ** <b>The "DROP TABLE" Exception</b> 7906 ** 7907 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7908 ** always appropriate to call sqlite3_unlock_notify(). There is however, 7909 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7910 ** SQLite checks if there are any currently executing SELECT statements 7911 ** that belong to the same connection. If there are, SQLITE_LOCKED is 7912 ** returned. In this case there is no "blocking connection", so invoking 7913 ** sqlite3_unlock_notify() results in the unlock-notify callback being 7914 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 7915 ** or "DROP INDEX" query, an infinite loop might be the result. 7916 ** 7917 ** One way around this problem is to check the extended error code returned 7918 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7919 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7920 ** the special "DROP TABLE/INDEX" case, the extended error code is just 7921 ** SQLITE_LOCKED.)^ 7922 */ 7923 SQLITE_API int sqlite3_unlock_notify( 7924 sqlite3 *pBlocked, /* Waiting connection */ 7925 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7926 void *pNotifyArg /* Argument to pass to xNotify */ 7927 ); 7928 7929 7930 /* 7931 ** CAPI3REF: String Comparison 7932 ** 7933 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7934 ** and extensions to compare the contents of two buffers containing UTF-8 7935 ** strings in a case-independent fashion, using the same definition of "case 7936 ** independence" that SQLite uses internally when comparing identifiers. 7937 */ 7938 SQLITE_API int sqlite3_stricmp(const char *, const char *); 7939 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 7940 7941 /* 7942 ** CAPI3REF: String Globbing 7943 * 7944 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 7945 ** string X matches the [GLOB] pattern P. 7946 ** ^The definition of [GLOB] pattern matching used in 7947 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7948 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 7949 ** is case sensitive. 7950 ** 7951 ** Note that this routine returns zero on a match and non-zero if the strings 7952 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7953 ** 7954 ** See also: [sqlite3_strlike()]. 7955 */ 7956 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 7957 7958 /* 7959 ** CAPI3REF: String LIKE Matching 7960 * 7961 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 7962 ** string X matches the [LIKE] pattern P with escape character E. 7963 ** ^The definition of [LIKE] pattern matching used in 7964 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 7965 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 7966 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 7967 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 7968 ** insensitive - equivalent upper and lower case ASCII characters match 7969 ** one another. 7970 ** 7971 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 7972 ** only ASCII characters are case folded. 7973 ** 7974 ** Note that this routine returns zero on a match and non-zero if the strings 7975 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7976 ** 7977 ** See also: [sqlite3_strglob()]. 7978 */ 7979 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 7980 7981 /* 7982 ** CAPI3REF: Error Logging Interface 7983 ** 7984 ** ^The [sqlite3_log()] interface writes a message into the [error log] 7985 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7986 ** ^If logging is enabled, the zFormat string and subsequent arguments are 7987 ** used with [sqlite3_snprintf()] to generate the final output string. 7988 ** 7989 ** The sqlite3_log() interface is intended for use by extensions such as 7990 ** virtual tables, collating functions, and SQL functions. While there is 7991 ** nothing to prevent an application from calling sqlite3_log(), doing so 7992 ** is considered bad form. 7993 ** 7994 ** The zFormat string must not be NULL. 7995 ** 7996 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7997 ** will not use dynamically allocated memory. The log message is stored in 7998 ** a fixed-length buffer on the stack. If the log message is longer than 7999 ** a few hundred characters, it will be truncated to the length of the 8000 ** buffer. 8001 */ 8002 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 8003 8004 /* 8005 ** CAPI3REF: Write-Ahead Log Commit Hook 8006 ** METHOD: sqlite3 8007 ** 8008 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 8009 ** is invoked each time data is committed to a database in wal mode. 8010 ** 8011 ** ^(The callback is invoked by SQLite after the commit has taken place and 8012 ** the associated write-lock on the database released)^, so the implementation 8013 ** may read, write or [checkpoint] the database as required. 8014 ** 8015 ** ^The first parameter passed to the callback function when it is invoked 8016 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 8017 ** registering the callback. ^The second is a copy of the database handle. 8018 ** ^The third parameter is the name of the database that was written to - 8019 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8020 ** is the number of pages currently in the write-ahead log file, 8021 ** including those that were just committed. 8022 ** 8023 ** The callback function should normally return [SQLITE_OK]. ^If an error 8024 ** code is returned, that error will propagate back up through the 8025 ** SQLite code base to cause the statement that provoked the callback 8026 ** to report an error, though the commit will have still occurred. If the 8027 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8028 ** that does not correspond to any valid SQLite error code, the results 8029 ** are undefined. 8030 ** 8031 ** A single database handle may have at most a single write-ahead log callback 8032 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8033 ** previously registered write-ahead log callback. ^Note that the 8034 ** [sqlite3_wal_autocheckpoint()] interface and the 8035 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8036 ** overwrite any prior [sqlite3_wal_hook()] settings. 8037 */ 8038 SQLITE_API void *sqlite3_wal_hook( 8039 sqlite3*, 8040 int(*)(void *,sqlite3*,const char*,int), 8041 void* 8042 ); 8043 8044 /* 8045 ** CAPI3REF: Configure an auto-checkpoint 8046 ** METHOD: sqlite3 8047 ** 8048 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8049 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 8050 ** to automatically [checkpoint] 8051 ** after committing a transaction if there are N or 8052 ** more frames in the [write-ahead log] file. ^Passing zero or 8053 ** a negative value as the nFrame parameter disables automatic 8054 ** checkpoints entirely. 8055 ** 8056 ** ^The callback registered by this function replaces any existing callback 8057 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8058 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8059 ** configured by this function. 8060 ** 8061 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8062 ** from SQL. 8063 ** 8064 ** ^Checkpoints initiated by this mechanism are 8065 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8066 ** 8067 ** ^Every new [database connection] defaults to having the auto-checkpoint 8068 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8069 ** pages. The use of this interface 8070 ** is only necessary if the default setting is found to be suboptimal 8071 ** for a particular application. 8072 */ 8073 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8074 8075 /* 8076 ** CAPI3REF: Checkpoint a database 8077 ** METHOD: sqlite3 8078 ** 8079 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8080 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8081 ** 8082 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8083 ** [write-ahead log] for database X on [database connection] D to be 8084 ** transferred into the database file and for the write-ahead log to 8085 ** be reset. See the [checkpointing] documentation for addition 8086 ** information. 8087 ** 8088 ** This interface used to be the only way to cause a checkpoint to 8089 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8090 ** interface was added. This interface is retained for backwards 8091 ** compatibility and as a convenience for applications that need to manually 8092 ** start a callback but which do not need the full power (and corresponding 8093 ** complication) of [sqlite3_wal_checkpoint_v2()]. 8094 */ 8095 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8096 8097 /* 8098 ** CAPI3REF: Checkpoint a database 8099 ** METHOD: sqlite3 8100 ** 8101 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8102 ** operation on database X of [database connection] D in mode M. Status 8103 ** information is written back into integers pointed to by L and C.)^ 8104 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 8105 ** 8106 ** <dl> 8107 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8108 ** ^Checkpoint as many frames as possible without waiting for any database 8109 ** readers or writers to finish, then sync the database file if all frames 8110 ** in the log were checkpointed. ^The [busy-handler callback] 8111 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8112 ** ^On the other hand, passive mode might leave the checkpoint unfinished 8113 ** if there are concurrent readers or writers. 8114 ** 8115 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 8116 ** ^This mode blocks (it invokes the 8117 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 8118 ** database writer and all readers are reading from the most recent database 8119 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 8120 ** database file. ^This mode blocks new database writers while it is pending, 8121 ** but new database readers are allowed to continue unimpeded. 8122 ** 8123 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 8124 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 8125 ** that after checkpointing the log file it blocks (calls the 8126 ** [busy-handler callback]) 8127 ** until all readers are reading from the database file only. ^This ensures 8128 ** that the next writer will restart the log file from the beginning. 8129 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 8130 ** database writer attempts while it is pending, but does not impede readers. 8131 ** 8132 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 8133 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 8134 ** addition that it also truncates the log file to zero bytes just prior 8135 ** to a successful return. 8136 ** </dl> 8137 ** 8138 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 8139 ** the log file or to -1 if the checkpoint could not run because 8140 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 8141 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 8142 ** log file (including any that were already checkpointed before the function 8143 ** was called) or to -1 if the checkpoint could not run due to an error or 8144 ** because the database is not in WAL mode. ^Note that upon successful 8145 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 8146 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 8147 ** 8148 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 8149 ** any other process is running a checkpoint operation at the same time, the 8150 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 8151 ** busy-handler configured, it will not be invoked in this case. 8152 ** 8153 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 8154 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 8155 ** obtained immediately, and a busy-handler is configured, it is invoked and 8156 ** the writer lock retried until either the busy-handler returns 0 or the lock 8157 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 8158 ** database readers as described above. ^If the busy-handler returns 0 before 8159 ** the writer lock is obtained or while waiting for database readers, the 8160 ** checkpoint operation proceeds from that point in the same way as 8161 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 8162 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 8163 ** 8164 ** ^If parameter zDb is NULL or points to a zero length string, then the 8165 ** specified operation is attempted on all WAL databases [attached] to 8166 ** [database connection] db. In this case the 8167 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 8168 ** an SQLITE_BUSY error is encountered when processing one or more of the 8169 ** attached WAL databases, the operation is still attempted on any remaining 8170 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 8171 ** error occurs while processing an attached database, processing is abandoned 8172 ** and the error code is returned to the caller immediately. ^If no error 8173 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 8174 ** databases, SQLITE_OK is returned. 8175 ** 8176 ** ^If database zDb is the name of an attached database that is not in WAL 8177 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 8178 ** zDb is not NULL (or a zero length string) and is not the name of any 8179 ** attached database, SQLITE_ERROR is returned to the caller. 8180 ** 8181 ** ^Unless it returns SQLITE_MISUSE, 8182 ** the sqlite3_wal_checkpoint_v2() interface 8183 ** sets the error information that is queried by 8184 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 8185 ** 8186 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 8187 ** from SQL. 8188 */ 8189 SQLITE_API int sqlite3_wal_checkpoint_v2( 8190 sqlite3 *db, /* Database handle */ 8191 const char *zDb, /* Name of attached database (or NULL) */ 8192 int eMode, /* SQLITE_CHECKPOINT_* value */ 8193 int *pnLog, /* OUT: Size of WAL log in frames */ 8194 int *pnCkpt /* OUT: Total number of frames checkpointed */ 8195 ); 8196 8197 /* 8198 ** CAPI3REF: Checkpoint Mode Values 8199 ** KEYWORDS: {checkpoint mode} 8200 ** 8201 ** These constants define all valid values for the "checkpoint mode" passed 8202 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 8203 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 8204 ** meaning of each of these checkpoint modes. 8205 */ 8206 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 8207 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 8208 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 8209 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 8210 8211 /* 8212 ** CAPI3REF: Virtual Table Interface Configuration 8213 ** 8214 ** This function may be called by either the [xConnect] or [xCreate] method 8215 ** of a [virtual table] implementation to configure 8216 ** various facets of the virtual table interface. 8217 ** 8218 ** If this interface is invoked outside the context of an xConnect or 8219 ** xCreate virtual table method then the behavior is undefined. 8220 ** 8221 ** At present, there is only one option that may be configured using 8222 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 8223 ** may be added in the future. 8224 */ 8225 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 8226 8227 /* 8228 ** CAPI3REF: Virtual Table Configuration Options 8229 ** 8230 ** These macros define the various options to the 8231 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 8232 ** can use to customize and optimize their behavior. 8233 ** 8234 ** <dl> 8235 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 8236 ** <dd>Calls of the form 8237 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 8238 ** where X is an integer. If X is zero, then the [virtual table] whose 8239 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 8240 ** support constraints. In this configuration (which is the default) if 8241 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 8242 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 8243 ** specified as part of the users SQL statement, regardless of the actual 8244 ** ON CONFLICT mode specified. 8245 ** 8246 ** If X is non-zero, then the virtual table implementation guarantees 8247 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 8248 ** any modifications to internal or persistent data structures have been made. 8249 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 8250 ** is able to roll back a statement or database transaction, and abandon 8251 ** or continue processing the current SQL statement as appropriate. 8252 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 8253 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 8254 ** had been ABORT. 8255 ** 8256 ** Virtual table implementations that are required to handle OR REPLACE 8257 ** must do so within the [xUpdate] method. If a call to the 8258 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 8259 ** CONFLICT policy is REPLACE, the virtual table implementation should 8260 ** silently replace the appropriate rows within the xUpdate callback and 8261 ** return SQLITE_OK. Or, if this is not possible, it may return 8262 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 8263 ** constraint handling. 8264 ** </dl> 8265 */ 8266 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 8267 8268 /* 8269 ** CAPI3REF: Determine The Virtual Table Conflict Policy 8270 ** 8271 ** This function may only be called from within a call to the [xUpdate] method 8272 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 8273 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 8274 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8275 ** of the SQL statement that triggered the call to the [xUpdate] method of the 8276 ** [virtual table]. 8277 */ 8278 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 8279 8280 /* 8281 ** CAPI3REF: Conflict resolution modes 8282 ** KEYWORDS: {conflict resolution mode} 8283 ** 8284 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 8285 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 8286 ** is for the SQL statement being evaluated. 8287 ** 8288 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 8289 ** return value from the [sqlite3_set_authorizer()] callback and that 8290 ** [SQLITE_ABORT] is also a [result code]. 8291 */ 8292 #define SQLITE_ROLLBACK 1 8293 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8294 #define SQLITE_FAIL 3 8295 /* #define SQLITE_ABORT 4 // Also an error code */ 8296 #define SQLITE_REPLACE 5 8297 8298 /* 8299 ** CAPI3REF: Prepared Statement Scan Status Opcodes 8300 ** KEYWORDS: {scanstatus options} 8301 ** 8302 ** The following constants can be used for the T parameter to the 8303 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8304 ** different metric for sqlite3_stmt_scanstatus() to return. 8305 ** 8306 ** When the value returned to V is a string, space to hold that string is 8307 ** managed by the prepared statement S and will be automatically freed when 8308 ** S is finalized. 8309 ** 8310 ** <dl> 8311 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8312 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8313 ** set to the total number of times that the X-th loop has run.</dd> 8314 ** 8315 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8316 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8317 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 8318 ** 8319 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8320 ** <dd>^The "double" variable pointed to by the T parameter will be set to the 8321 ** query planner's estimate for the average number of rows output from each 8322 ** iteration of the X-th loop. If the query planner's estimates was accurate, 8323 ** then this value will approximate the quotient NVISIT/NLOOP and the 8324 ** product of this value for all prior loops with the same SELECTID will 8325 ** be the NLOOP value for the current loop. 8326 ** 8327 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8328 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8329 ** to a zero-terminated UTF-8 string containing the name of the index or table 8330 ** used for the X-th loop. 8331 ** 8332 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8333 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8334 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8335 ** description for the X-th loop. 8336 ** 8337 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8338 ** <dd>^The "int" variable pointed to by the T parameter will be set to the 8339 ** "select-id" for the X-th loop. The select-id identifies which query or 8340 ** subquery the loop is part of. The main query has a select-id of zero. 8341 ** The select-id is the same value as is output in the first column 8342 ** of an [EXPLAIN QUERY PLAN] query. 8343 ** </dl> 8344 */ 8345 #define SQLITE_SCANSTAT_NLOOP 0 8346 #define SQLITE_SCANSTAT_NVISIT 1 8347 #define SQLITE_SCANSTAT_EST 2 8348 #define SQLITE_SCANSTAT_NAME 3 8349 #define SQLITE_SCANSTAT_EXPLAIN 4 8350 #define SQLITE_SCANSTAT_SELECTID 5 8351 8352 /* 8353 ** CAPI3REF: Prepared Statement Scan Status 8354 ** METHOD: sqlite3_stmt 8355 ** 8356 ** This interface returns information about the predicted and measured 8357 ** performance for pStmt. Advanced applications can use this 8358 ** interface to compare the predicted and the measured performance and 8359 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8360 ** 8361 ** Since this interface is expected to be rarely used, it is only 8362 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8363 ** compile-time option. 8364 ** 8365 ** The "iScanStatusOp" parameter determines which status information to return. 8366 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8367 ** of this interface is undefined. 8368 ** ^The requested measurement is written into a variable pointed to by 8369 ** the "pOut" parameter. 8370 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 8371 ** Loops are numbered starting from zero. ^If idx is out of range - less than 8372 ** zero or greater than or equal to the total number of loops used to implement 8373 ** the statement - a non-zero value is returned and the variable that pOut 8374 ** points to is unchanged. 8375 ** 8376 ** ^Statistics might not be available for all loops in all statements. ^In cases 8377 ** where there exist loops with no available statistics, this function behaves 8378 ** as if the loop did not exist - it returns non-zero and leave the variable 8379 ** that pOut points to unchanged. 8380 ** 8381 ** See also: [sqlite3_stmt_scanstatus_reset()] 8382 */ 8383 SQLITE_API int sqlite3_stmt_scanstatus( 8384 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8385 int idx, /* Index of loop to report on */ 8386 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8387 void *pOut /* Result written here */ 8388 ); 8389 8390 /* 8391 ** CAPI3REF: Zero Scan-Status Counters 8392 ** METHOD: sqlite3_stmt 8393 ** 8394 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8395 ** 8396 ** This API is only available if the library is built with pre-processor 8397 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8398 */ 8399 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8400 8401 /* 8402 ** CAPI3REF: Flush caches to disk mid-transaction 8403 ** 8404 ** ^If a write-transaction is open on [database connection] D when the 8405 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8406 ** pages in the pager-cache that are not currently in use are written out 8407 ** to disk. A dirty page may be in use if a database cursor created by an 8408 ** active SQL statement is reading from it, or if it is page 1 of a database 8409 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8410 ** interface flushes caches for all schemas - "main", "temp", and 8411 ** any [attached] databases. 8412 ** 8413 ** ^If this function needs to obtain extra database locks before dirty pages 8414 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 8415 ** immediately and there is a busy-handler callback configured, it is invoked 8416 ** in the usual manner. ^If the required lock still cannot be obtained, then 8417 ** the database is skipped and an attempt made to flush any dirty pages 8418 ** belonging to the next (if any) database. ^If any databases are skipped 8419 ** because locks cannot be obtained, but no other error occurs, this 8420 ** function returns SQLITE_BUSY. 8421 ** 8422 ** ^If any other error occurs while flushing dirty pages to disk (for 8423 ** example an IO error or out-of-memory condition), then processing is 8424 ** abandoned and an SQLite [error code] is returned to the caller immediately. 8425 ** 8426 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8427 ** 8428 ** ^This function does not set the database handle error code or message 8429 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8430 */ 8431 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 8432 8433 /* 8434 ** CAPI3REF: The pre-update hook. 8435 ** 8436 ** ^These interfaces are only available if SQLite is compiled using the 8437 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8438 ** 8439 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8440 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8441 ** on a database table. 8442 ** ^At most one preupdate hook may be registered at a time on a single 8443 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8444 ** the previous setting. 8445 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8446 ** with a NULL pointer as the second parameter. 8447 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8448 ** the first parameter to callbacks. 8449 ** 8450 ** ^The preupdate hook only fires for changes to real database tables; the 8451 ** preupdate hook is not invoked for changes to [virtual tables] or to 8452 ** system tables like sqlite_master or sqlite_stat1. 8453 ** 8454 ** ^The second parameter to the preupdate callback is a pointer to 8455 ** the [database connection] that registered the preupdate hook. 8456 ** ^The third parameter to the preupdate callback is one of the constants 8457 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 8458 ** kind of update operation that is about to occur. 8459 ** ^(The fourth parameter to the preupdate callback is the name of the 8460 ** database within the database connection that is being modified. This 8461 ** will be "main" for the main database or "temp" for TEMP tables or 8462 ** the name given after the AS keyword in the [ATTACH] statement for attached 8463 ** databases.)^ 8464 ** ^The fifth parameter to the preupdate callback is the name of the 8465 ** table that is being modified. 8466 ** 8467 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 8468 ** parameter passed to the preupdate callback is the initial [rowid] of the 8469 ** row being modified or deleted. For an INSERT operation on a rowid table, 8470 ** or any operation on a WITHOUT ROWID table, the value of the sixth 8471 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 8472 ** seventh parameter is the final rowid value of the row being inserted 8473 ** or updated. The value of the seventh parameter passed to the callback 8474 ** function is not defined for operations on WITHOUT ROWID tables, or for 8475 ** INSERT operations on rowid tables. 8476 ** 8477 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 8478 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 8479 ** provide additional information about a preupdate event. These routines 8480 ** may only be called from within a preupdate callback. Invoking any of 8481 ** these routines from outside of a preupdate callback or with a 8482 ** [database connection] pointer that is different from the one supplied 8483 ** to the preupdate callback results in undefined and probably undesirable 8484 ** behavior. 8485 ** 8486 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 8487 ** in the row that is being inserted, updated, or deleted. 8488 ** 8489 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 8490 ** a [protected sqlite3_value] that contains the value of the Nth column of 8491 ** the table row before it is updated. The N parameter must be between 0 8492 ** and one less than the number of columns or the behavior will be 8493 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 8494 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 8495 ** behavior is undefined. The [sqlite3_value] that P points to 8496 ** will be destroyed when the preupdate callback returns. 8497 ** 8498 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 8499 ** a [protected sqlite3_value] that contains the value of the Nth column of 8500 ** the table row after it is updated. The N parameter must be between 0 8501 ** and one less than the number of columns or the behavior will be 8502 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 8503 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 8504 ** behavior is undefined. The [sqlite3_value] that P points to 8505 ** will be destroyed when the preupdate callback returns. 8506 ** 8507 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 8508 ** callback was invoked as a result of a direct insert, update, or delete 8509 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 8510 ** triggers; or 2 for changes resulting from triggers called by top-level 8511 ** triggers; and so forth. 8512 ** 8513 ** See also: [sqlite3_update_hook()] 8514 */ 8515 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 8516 SQLITE_API void *sqlite3_preupdate_hook( 8517 sqlite3 *db, 8518 void(*xPreUpdate)( 8519 void *pCtx, /* Copy of third arg to preupdate_hook() */ 8520 sqlite3 *db, /* Database handle */ 8521 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 8522 char const *zDb, /* Database name */ 8523 char const *zName, /* Table name */ 8524 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 8525 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 8526 ), 8527 void* 8528 ); 8529 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 8530 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 8531 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 8532 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 8533 #endif 8534 8535 /* 8536 ** CAPI3REF: Low-level system error code 8537 ** 8538 ** ^Attempt to return the underlying operating system error code or error 8539 ** number that caused the most recent I/O error or failure to open a file. 8540 ** The return value is OS-dependent. For example, on unix systems, after 8541 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 8542 ** called to get back the underlying "errno" that caused the problem, such 8543 ** as ENOSPC, EAUTH, EISDIR, and so forth. 8544 */ 8545 SQLITE_API int sqlite3_system_errno(sqlite3*); 8546 8547 /* 8548 ** CAPI3REF: Database Snapshot 8549 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 8550 ** EXPERIMENTAL 8551 ** 8552 ** An instance of the snapshot object records the state of a [WAL mode] 8553 ** database for some specific point in history. 8554 ** 8555 ** In [WAL mode], multiple [database connections] that are open on the 8556 ** same database file can each be reading a different historical version 8557 ** of the database file. When a [database connection] begins a read 8558 ** transaction, that connection sees an unchanging copy of the database 8559 ** as it existed for the point in time when the transaction first started. 8560 ** Subsequent changes to the database from other connections are not seen 8561 ** by the reader until a new read transaction is started. 8562 ** 8563 ** The sqlite3_snapshot object records state information about an historical 8564 ** version of the database file so that it is possible to later open a new read 8565 ** transaction that sees that historical version of the database rather than 8566 ** the most recent version. 8567 ** 8568 ** The constructor for this object is [sqlite3_snapshot_get()]. The 8569 ** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer 8570 ** to an historical snapshot (if possible). The destructor for 8571 ** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. 8572 */ 8573 typedef struct sqlite3_snapshot { 8574 unsigned char hidden[48]; 8575 } sqlite3_snapshot; 8576 8577 /* 8578 ** CAPI3REF: Record A Database Snapshot 8579 ** EXPERIMENTAL 8580 ** 8581 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 8582 ** new [sqlite3_snapshot] object that records the current state of 8583 ** schema S in database connection D. ^On success, the 8584 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 8585 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 8586 ** If there is not already a read-transaction open on schema S when 8587 ** this function is called, one is opened automatically. 8588 ** 8589 ** The following must be true for this function to succeed. If any of 8590 ** the following statements are false when sqlite3_snapshot_get() is 8591 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 8592 ** in this case. 8593 ** 8594 ** <ul> 8595 ** <li> The database handle must be in [autocommit mode]. 8596 ** 8597 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 8598 ** 8599 ** <li> There must not be a write transaction open on schema S of database 8600 ** connection D. 8601 ** 8602 ** <li> One or more transactions must have been written to the current wal 8603 ** file since it was created on disk (by any connection). This means 8604 ** that a snapshot cannot be taken on a wal mode database with no wal 8605 ** file immediately after it is first opened. At least one transaction 8606 ** must be written to it first. 8607 ** </ul> 8608 ** 8609 ** This function may also return SQLITE_NOMEM. If it is called with the 8610 ** database handle in autocommit mode but fails for some other reason, 8611 ** whether or not a read transaction is opened on schema S is undefined. 8612 ** 8613 ** The [sqlite3_snapshot] object returned from a successful call to 8614 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 8615 ** to avoid a memory leak. 8616 ** 8617 ** The [sqlite3_snapshot_get()] interface is only available when the 8618 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8619 */ 8620 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 8621 sqlite3 *db, 8622 const char *zSchema, 8623 sqlite3_snapshot **ppSnapshot 8624 ); 8625 8626 /* 8627 ** CAPI3REF: Start a read transaction on an historical snapshot 8628 ** EXPERIMENTAL 8629 ** 8630 ** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a 8631 ** read transaction for schema S of 8632 ** [database connection] D such that the read transaction 8633 ** refers to historical [snapshot] P, rather than the most 8634 ** recent change to the database. 8635 ** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success 8636 ** or an appropriate [error code] if it fails. 8637 ** 8638 ** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be 8639 ** the first operation following the [BEGIN] that takes the schema S 8640 ** out of [autocommit mode]. 8641 ** ^In other words, schema S must not currently be in 8642 ** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the 8643 ** database connection D must be out of [autocommit mode]. 8644 ** ^A [snapshot] will fail to open if it has been overwritten by a 8645 ** [checkpoint]. 8646 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 8647 ** database connection D does not know that the database file for 8648 ** schema S is in [WAL mode]. A database connection might not know 8649 ** that the database file is in [WAL mode] if there has been no prior 8650 ** I/O on that database connection, or if the database entered [WAL mode] 8651 ** after the most recent I/O on the database connection.)^ 8652 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 8653 ** database connection in order to make it ready to use snapshots.) 8654 ** 8655 ** The [sqlite3_snapshot_open()] interface is only available when the 8656 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8657 */ 8658 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 8659 sqlite3 *db, 8660 const char *zSchema, 8661 sqlite3_snapshot *pSnapshot 8662 ); 8663 8664 /* 8665 ** CAPI3REF: Destroy a snapshot 8666 ** EXPERIMENTAL 8667 ** 8668 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 8669 ** The application must eventually free every [sqlite3_snapshot] object 8670 ** using this routine to avoid a memory leak. 8671 ** 8672 ** The [sqlite3_snapshot_free()] interface is only available when the 8673 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8674 */ 8675 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 8676 8677 /* 8678 ** CAPI3REF: Compare the ages of two snapshot handles. 8679 ** EXPERIMENTAL 8680 ** 8681 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 8682 ** of two valid snapshot handles. 8683 ** 8684 ** If the two snapshot handles are not associated with the same database 8685 ** file, the result of the comparison is undefined. 8686 ** 8687 ** Additionally, the result of the comparison is only valid if both of the 8688 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 8689 ** last time the wal file was deleted. The wal file is deleted when the 8690 ** database is changed back to rollback mode or when the number of database 8691 ** clients drops to zero. If either snapshot handle was obtained before the 8692 ** wal file was last deleted, the value returned by this function 8693 ** is undefined. 8694 ** 8695 ** Otherwise, this API returns a negative value if P1 refers to an older 8696 ** snapshot than P2, zero if the two handles refer to the same database 8697 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 8698 */ 8699 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 8700 sqlite3_snapshot *p1, 8701 sqlite3_snapshot *p2 8702 ); 8703 8704 /* 8705 ** CAPI3REF: Recover snapshots from a wal file 8706 ** EXPERIMENTAL 8707 ** 8708 ** If all connections disconnect from a database file but do not perform 8709 ** a checkpoint, the existing wal file is opened along with the database 8710 ** file the next time the database is opened. At this point it is only 8711 ** possible to successfully call sqlite3_snapshot_open() to open the most 8712 ** recent snapshot of the database (the one at the head of the wal file), 8713 ** even though the wal file may contain other valid snapshots for which 8714 ** clients have sqlite3_snapshot handles. 8715 ** 8716 ** This function attempts to scan the wal file associated with database zDb 8717 ** of database handle db and make all valid snapshots available to 8718 ** sqlite3_snapshot_open(). It is an error if there is already a read 8719 ** transaction open on the database, or if the database is not a wal mode 8720 ** database. 8721 ** 8722 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 8723 */ 8724 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 8725 8726 /* 8727 ** Undo the hack that converts floating point types to integer for 8728 ** builds on processors without floating point support. 8729 */ 8730 #ifdef SQLITE_OMIT_FLOATING_POINT 8731 # undef double 8732 #endif 8733 8734 #ifdef __cplusplus 8735 } /* End of the 'extern "C"' block */ 8736 #endif 8737 #endif /* SQLITE3_H */ 8738 8739 /******** Begin file sqlite3rtree.h *********/ 8740 /* 8741 ** 2010 August 30 8742 ** 8743 ** The author disclaims copyright to this source code. In place of 8744 ** a legal notice, here is a blessing: 8745 ** 8746 ** May you do good and not evil. 8747 ** May you find forgiveness for yourself and forgive others. 8748 ** May you share freely, never taking more than you give. 8749 ** 8750 ************************************************************************* 8751 */ 8752 8753 #ifndef _SQLITE3RTREE_H_ 8754 #define _SQLITE3RTREE_H_ 8755 8756 8757 #ifdef __cplusplus 8758 extern "C" { 8759 #endif 8760 8761 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 8762 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 8763 8764 /* The double-precision datatype used by RTree depends on the 8765 ** SQLITE_RTREE_INT_ONLY compile-time option. 8766 */ 8767 #ifdef SQLITE_RTREE_INT_ONLY 8768 typedef sqlite3_int64 sqlite3_rtree_dbl; 8769 #else 8770 typedef double sqlite3_rtree_dbl; 8771 #endif 8772 8773 /* 8774 ** Register a geometry callback named zGeom that can be used as part of an 8775 ** R-Tree geometry query as follows: 8776 ** 8777 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 8778 */ 8779 SQLITE_API int sqlite3_rtree_geometry_callback( 8780 sqlite3 *db, 8781 const char *zGeom, 8782 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 8783 void *pContext 8784 ); 8785 8786 8787 /* 8788 ** A pointer to a structure of the following type is passed as the first 8789 ** argument to callbacks registered using rtree_geometry_callback(). 8790 */ 8791 struct sqlite3_rtree_geometry { 8792 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 8793 int nParam; /* Size of array aParam[] */ 8794 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 8795 void *pUser; /* Callback implementation user data */ 8796 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 8797 }; 8798 8799 /* 8800 ** Register a 2nd-generation geometry callback named zScore that can be 8801 ** used as part of an R-Tree geometry query as follows: 8802 ** 8803 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 8804 */ 8805 SQLITE_API int sqlite3_rtree_query_callback( 8806 sqlite3 *db, 8807 const char *zQueryFunc, 8808 int (*xQueryFunc)(sqlite3_rtree_query_info*), 8809 void *pContext, 8810 void (*xDestructor)(void*) 8811 ); 8812 8813 8814 /* 8815 ** A pointer to a structure of the following type is passed as the 8816 ** argument to scored geometry callback registered using 8817 ** sqlite3_rtree_query_callback(). 8818 ** 8819 ** Note that the first 5 fields of this structure are identical to 8820 ** sqlite3_rtree_geometry. This structure is a subclass of 8821 ** sqlite3_rtree_geometry. 8822 */ 8823 struct sqlite3_rtree_query_info { 8824 void *pContext; /* pContext from when function registered */ 8825 int nParam; /* Number of function parameters */ 8826 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 8827 void *pUser; /* callback can use this, if desired */ 8828 void (*xDelUser)(void*); /* function to free pUser */ 8829 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 8830 unsigned int *anQueue; /* Number of pending entries in the queue */ 8831 int nCoord; /* Number of coordinates */ 8832 int iLevel; /* Level of current node or entry */ 8833 int mxLevel; /* The largest iLevel value in the tree */ 8834 sqlite3_int64 iRowid; /* Rowid for current entry */ 8835 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 8836 int eParentWithin; /* Visibility of parent node */ 8837 int eWithin; /* OUT: Visiblity */ 8838 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 8839 /* The following fields are only available in 3.8.11 and later */ 8840 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 8841 }; 8842 8843 /* 8844 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 8845 */ 8846 #define NOT_WITHIN 0 /* Object completely outside of query region */ 8847 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 8848 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 8849 8850 8851 #ifdef __cplusplus 8852 } /* end of the 'extern "C"' block */ 8853 #endif 8854 8855 #endif /* ifndef _SQLITE3RTREE_H_ */ 8856 8857 /******** End of sqlite3rtree.h *********/ 8858 /******** Begin file sqlite3session.h *********/ 8859 8860 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 8861 #define __SQLITESESSION_H_ 1 8862 8863 /* 8864 ** Make sure we can call this stuff from C++. 8865 */ 8866 #ifdef __cplusplus 8867 extern "C" { 8868 #endif 8869 8870 8871 /* 8872 ** CAPI3REF: Session Object Handle 8873 */ 8874 typedef struct sqlite3_session sqlite3_session; 8875 8876 /* 8877 ** CAPI3REF: Changeset Iterator Handle 8878 */ 8879 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 8880 8881 /* 8882 ** CAPI3REF: Create A New Session Object 8883 ** 8884 ** Create a new session object attached to database handle db. If successful, 8885 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 8886 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 8887 ** error code (e.g. SQLITE_NOMEM) is returned. 8888 ** 8889 ** It is possible to create multiple session objects attached to a single 8890 ** database handle. 8891 ** 8892 ** Session objects created using this function should be deleted using the 8893 ** [sqlite3session_delete()] function before the database handle that they 8894 ** are attached to is itself closed. If the database handle is closed before 8895 ** the session object is deleted, then the results of calling any session 8896 ** module function, including [sqlite3session_delete()] on the session object 8897 ** are undefined. 8898 ** 8899 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 8900 ** is not possible for an application to register a pre-update hook on a 8901 ** database handle that has one or more session objects attached. Nor is 8902 ** it possible to create a session object attached to a database handle for 8903 ** which a pre-update hook is already defined. The results of attempting 8904 ** either of these things are undefined. 8905 ** 8906 ** The session object will be used to create changesets for tables in 8907 ** database zDb, where zDb is either "main", or "temp", or the name of an 8908 ** attached database. It is not an error if database zDb is not attached 8909 ** to the database when the session object is created. 8910 */ 8911 SQLITE_API int sqlite3session_create( 8912 sqlite3 *db, /* Database handle */ 8913 const char *zDb, /* Name of db (e.g. "main") */ 8914 sqlite3_session **ppSession /* OUT: New session object */ 8915 ); 8916 8917 /* 8918 ** CAPI3REF: Delete A Session Object 8919 ** 8920 ** Delete a session object previously allocated using 8921 ** [sqlite3session_create()]. Once a session object has been deleted, the 8922 ** results of attempting to use pSession with any other session module 8923 ** function are undefined. 8924 ** 8925 ** Session objects must be deleted before the database handle to which they 8926 ** are attached is closed. Refer to the documentation for 8927 ** [sqlite3session_create()] for details. 8928 */ 8929 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 8930 8931 8932 /* 8933 ** CAPI3REF: Enable Or Disable A Session Object 8934 ** 8935 ** Enable or disable the recording of changes by a session object. When 8936 ** enabled, a session object records changes made to the database. When 8937 ** disabled - it does not. A newly created session object is enabled. 8938 ** Refer to the documentation for [sqlite3session_changeset()] for further 8939 ** details regarding how enabling and disabling a session object affects 8940 ** the eventual changesets. 8941 ** 8942 ** Passing zero to this function disables the session. Passing a value 8943 ** greater than zero enables it. Passing a value less than zero is a 8944 ** no-op, and may be used to query the current state of the session. 8945 ** 8946 ** The return value indicates the final state of the session object: 0 if 8947 ** the session is disabled, or 1 if it is enabled. 8948 */ 8949 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 8950 8951 /* 8952 ** CAPI3REF: Set Or Clear the Indirect Change Flag 8953 ** 8954 ** Each change recorded by a session object is marked as either direct or 8955 ** indirect. A change is marked as indirect if either: 8956 ** 8957 ** <ul> 8958 ** <li> The session object "indirect" flag is set when the change is 8959 ** made, or 8960 ** <li> The change is made by an SQL trigger or foreign key action 8961 ** instead of directly as a result of a users SQL statement. 8962 ** </ul> 8963 ** 8964 ** If a single row is affected by more than one operation within a session, 8965 ** then the change is considered indirect if all operations meet the criteria 8966 ** for an indirect change above, or direct otherwise. 8967 ** 8968 ** This function is used to set, clear or query the session object indirect 8969 ** flag. If the second argument passed to this function is zero, then the 8970 ** indirect flag is cleared. If it is greater than zero, the indirect flag 8971 ** is set. Passing a value less than zero does not modify the current value 8972 ** of the indirect flag, and may be used to query the current state of the 8973 ** indirect flag for the specified session object. 8974 ** 8975 ** The return value indicates the final state of the indirect flag: 0 if 8976 ** it is clear, or 1 if it is set. 8977 */ 8978 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 8979 8980 /* 8981 ** CAPI3REF: Attach A Table To A Session Object 8982 ** 8983 ** If argument zTab is not NULL, then it is the name of a table to attach 8984 ** to the session object passed as the first argument. All subsequent changes 8985 ** made to the table while the session object is enabled will be recorded. See 8986 ** documentation for [sqlite3session_changeset()] for further details. 8987 ** 8988 ** Or, if argument zTab is NULL, then changes are recorded for all tables 8989 ** in the database. If additional tables are added to the database (by 8990 ** executing "CREATE TABLE" statements) after this call is made, changes for 8991 ** the new tables are also recorded. 8992 ** 8993 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 8994 ** defined as part of their CREATE TABLE statement. It does not matter if the 8995 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 8996 ** KEY may consist of a single column, or may be a composite key. 8997 ** 8998 ** It is not an error if the named table does not exist in the database. Nor 8999 ** is it an error if the named table does not have a PRIMARY KEY. However, 9000 ** no changes will be recorded in either of these scenarios. 9001 ** 9002 ** Changes are not recorded for individual rows that have NULL values stored 9003 ** in one or more of their PRIMARY KEY columns. 9004 ** 9005 ** SQLITE_OK is returned if the call completes without error. Or, if an error 9006 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 9007 */ 9008 SQLITE_API int sqlite3session_attach( 9009 sqlite3_session *pSession, /* Session object */ 9010 const char *zTab /* Table name */ 9011 ); 9012 9013 /* 9014 ** CAPI3REF: Set a table filter on a Session Object. 9015 ** 9016 ** The second argument (xFilter) is the "filter callback". For changes to rows 9017 ** in tables that are not attached to the Session object, the filter is called 9018 ** to determine whether changes to the table's rows should be tracked or not. 9019 ** If xFilter returns 0, changes is not tracked. Note that once a table is 9020 ** attached, xFilter will not be called again. 9021 */ 9022 SQLITE_API void sqlite3session_table_filter( 9023 sqlite3_session *pSession, /* Session object */ 9024 int(*xFilter)( 9025 void *pCtx, /* Copy of third arg to _filter_table() */ 9026 const char *zTab /* Table name */ 9027 ), 9028 void *pCtx /* First argument passed to xFilter */ 9029 ); 9030 9031 /* 9032 ** CAPI3REF: Generate A Changeset From A Session Object 9033 ** 9034 ** Obtain a changeset containing changes to the tables attached to the 9035 ** session object passed as the first argument. If successful, 9036 ** set *ppChangeset to point to a buffer containing the changeset 9037 ** and *pnChangeset to the size of the changeset in bytes before returning 9038 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 9039 ** zero and return an SQLite error code. 9040 ** 9041 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 9042 ** each representing a change to a single row of an attached table. An INSERT 9043 ** change contains the values of each field of a new database row. A DELETE 9044 ** contains the original values of each field of a deleted database row. An 9045 ** UPDATE change contains the original values of each field of an updated 9046 ** database row along with the updated values for each updated non-primary-key 9047 ** column. It is not possible for an UPDATE change to represent a change that 9048 ** modifies the values of primary key columns. If such a change is made, it 9049 ** is represented in a changeset as a DELETE followed by an INSERT. 9050 ** 9051 ** Changes are not recorded for rows that have NULL values stored in one or 9052 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 9053 ** no corresponding change is present in the changesets returned by this 9054 ** function. If an existing row with one or more NULL values stored in 9055 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 9056 ** only an INSERT is appears in the changeset. Similarly, if an existing row 9057 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 9058 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 9059 ** DELETE change only. 9060 ** 9061 ** The contents of a changeset may be traversed using an iterator created 9062 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 9063 ** a database with a compatible schema using the [sqlite3changeset_apply()] 9064 ** API. 9065 ** 9066 ** Within a changeset generated by this function, all changes related to a 9067 ** single table are grouped together. In other words, when iterating through 9068 ** a changeset or when applying a changeset to a database, all changes related 9069 ** to a single table are processed before moving on to the next table. Tables 9070 ** are sorted in the same order in which they were attached (or auto-attached) 9071 ** to the sqlite3_session object. The order in which the changes related to 9072 ** a single table are stored is undefined. 9073 ** 9074 ** Following a successful call to this function, it is the responsibility of 9075 ** the caller to eventually free the buffer that *ppChangeset points to using 9076 ** [sqlite3_free()]. 9077 ** 9078 ** <h3>Changeset Generation</h3> 9079 ** 9080 ** Once a table has been attached to a session object, the session object 9081 ** records the primary key values of all new rows inserted into the table. 9082 ** It also records the original primary key and other column values of any 9083 ** deleted or updated rows. For each unique primary key value, data is only 9084 ** recorded once - the first time a row with said primary key is inserted, 9085 ** updated or deleted in the lifetime of the session. 9086 ** 9087 ** There is one exception to the previous paragraph: when a row is inserted, 9088 ** updated or deleted, if one or more of its primary key columns contain a 9089 ** NULL value, no record of the change is made. 9090 ** 9091 ** The session object therefore accumulates two types of records - those 9092 ** that consist of primary key values only (created when the user inserts 9093 ** a new record) and those that consist of the primary key values and the 9094 ** original values of other table columns (created when the users deletes 9095 ** or updates a record). 9096 ** 9097 ** When this function is called, the requested changeset is created using 9098 ** both the accumulated records and the current contents of the database 9099 ** file. Specifically: 9100 ** 9101 ** <ul> 9102 ** <li> For each record generated by an insert, the database is queried 9103 ** for a row with a matching primary key. If one is found, an INSERT 9104 ** change is added to the changeset. If no such row is found, no change 9105 ** is added to the changeset. 9106 ** 9107 ** <li> For each record generated by an update or delete, the database is 9108 ** queried for a row with a matching primary key. If such a row is 9109 ** found and one or more of the non-primary key fields have been 9110 ** modified from their original values, an UPDATE change is added to 9111 ** the changeset. Or, if no such row is found in the table, a DELETE 9112 ** change is added to the changeset. If there is a row with a matching 9113 ** primary key in the database, but all fields contain their original 9114 ** values, no change is added to the changeset. 9115 ** </ul> 9116 ** 9117 ** This means, amongst other things, that if a row is inserted and then later 9118 ** deleted while a session object is active, neither the insert nor the delete 9119 ** will be present in the changeset. Or if a row is deleted and then later a 9120 ** row with the same primary key values inserted while a session object is 9121 ** active, the resulting changeset will contain an UPDATE change instead of 9122 ** a DELETE and an INSERT. 9123 ** 9124 ** When a session object is disabled (see the [sqlite3session_enable()] API), 9125 ** it does not accumulate records when rows are inserted, updated or deleted. 9126 ** This may appear to have some counter-intuitive effects if a single row 9127 ** is written to more than once during a session. For example, if a row 9128 ** is inserted while a session object is enabled, then later deleted while 9129 ** the same session object is disabled, no INSERT record will appear in the 9130 ** changeset, even though the delete took place while the session was disabled. 9131 ** Or, if one field of a row is updated while a session is disabled, and 9132 ** another field of the same row is updated while the session is enabled, the 9133 ** resulting changeset will contain an UPDATE change that updates both fields. 9134 */ 9135 SQLITE_API int sqlite3session_changeset( 9136 sqlite3_session *pSession, /* Session object */ 9137 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 9138 void **ppChangeset /* OUT: Buffer containing changeset */ 9139 ); 9140 9141 /* 9142 ** CAPI3REF: Load The Difference Between Tables Into A Session 9143 ** 9144 ** If it is not already attached to the session object passed as the first 9145 ** argument, this function attaches table zTbl in the same manner as the 9146 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 9147 ** does not have a primary key, this function is a no-op (but does not return 9148 ** an error). 9149 ** 9150 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 9151 ** attached to the same database handle as the session object that contains 9152 ** a table compatible with the table attached to the session by this function. 9153 ** A table is considered compatible if it: 9154 ** 9155 ** <ul> 9156 ** <li> Has the same name, 9157 ** <li> Has the same set of columns declared in the same order, and 9158 ** <li> Has the same PRIMARY KEY definition. 9159 ** </ul> 9160 ** 9161 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 9162 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 9163 ** but no changes are added to the session object. As with other session 9164 ** APIs, tables without PRIMARY KEYs are simply ignored. 9165 ** 9166 ** This function adds a set of changes to the session object that could be 9167 ** used to update the table in database zFrom (call this the "from-table") 9168 ** so that its content is the same as the table attached to the session 9169 ** object (call this the "to-table"). Specifically: 9170 ** 9171 ** <ul> 9172 ** <li> For each row (primary key) that exists in the to-table but not in 9173 ** the from-table, an INSERT record is added to the session object. 9174 ** 9175 ** <li> For each row (primary key) that exists in the to-table but not in 9176 ** the from-table, a DELETE record is added to the session object. 9177 ** 9178 ** <li> For each row (primary key) that exists in both tables, but features 9179 ** different non-PK values in each, an UPDATE record is added to the 9180 ** session. 9181 ** </ul> 9182 ** 9183 ** To clarify, if this function is called and then a changeset constructed 9184 ** using [sqlite3session_changeset()], then after applying that changeset to 9185 ** database zFrom the contents of the two compatible tables would be 9186 ** identical. 9187 ** 9188 ** It an error if database zFrom does not exist or does not contain the 9189 ** required compatible table. 9190 ** 9191 ** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite 9192 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 9193 ** may be set to point to a buffer containing an English language error 9194 ** message. It is the responsibility of the caller to free this buffer using 9195 ** sqlite3_free(). 9196 */ 9197 SQLITE_API int sqlite3session_diff( 9198 sqlite3_session *pSession, 9199 const char *zFromDb, 9200 const char *zTbl, 9201 char **pzErrMsg 9202 ); 9203 9204 9205 /* 9206 ** CAPI3REF: Generate A Patchset From A Session Object 9207 ** 9208 ** The differences between a patchset and a changeset are that: 9209 ** 9210 ** <ul> 9211 ** <li> DELETE records consist of the primary key fields only. The 9212 ** original values of other fields are omitted. 9213 ** <li> The original values of any modified fields are omitted from 9214 ** UPDATE records. 9215 ** </ul> 9216 ** 9217 ** A patchset blob may be used with up to date versions of all 9218 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 9219 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 9220 ** attempting to use a patchset blob with old versions of the 9221 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 9222 ** 9223 ** Because the non-primary key "old.*" fields are omitted, no 9224 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 9225 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 9226 ** in the same way as for changesets. 9227 ** 9228 ** Changes within a patchset are ordered in the same way as for changesets 9229 ** generated by the sqlite3session_changeset() function (i.e. all changes for 9230 ** a single table are grouped together, tables appear in the order in which 9231 ** they were attached to the session object). 9232 */ 9233 SQLITE_API int sqlite3session_patchset( 9234 sqlite3_session *pSession, /* Session object */ 9235 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 9236 void **ppPatchset /* OUT: Buffer containing patchset */ 9237 ); 9238 9239 /* 9240 ** CAPI3REF: Test if a changeset has recorded any changes. 9241 ** 9242 ** Return non-zero if no changes to attached tables have been recorded by 9243 ** the session object passed as the first argument. Otherwise, if one or 9244 ** more changes have been recorded, return zero. 9245 ** 9246 ** Even if this function returns zero, it is possible that calling 9247 ** [sqlite3session_changeset()] on the session handle may still return a 9248 ** changeset that contains no changes. This can happen when a row in 9249 ** an attached table is modified and then later on the original values 9250 ** are restored. However, if this function returns non-zero, then it is 9251 ** guaranteed that a call to sqlite3session_changeset() will return a 9252 ** changeset containing zero changes. 9253 */ 9254 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 9255 9256 /* 9257 ** CAPI3REF: Create An Iterator To Traverse A Changeset 9258 ** 9259 ** Create an iterator used to iterate through the contents of a changeset. 9260 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 9261 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 9262 ** SQLite error code is returned. 9263 ** 9264 ** The following functions can be used to advance and query a changeset 9265 ** iterator created by this function: 9266 ** 9267 ** <ul> 9268 ** <li> [sqlite3changeset_next()] 9269 ** <li> [sqlite3changeset_op()] 9270 ** <li> [sqlite3changeset_new()] 9271 ** <li> [sqlite3changeset_old()] 9272 ** </ul> 9273 ** 9274 ** It is the responsibility of the caller to eventually destroy the iterator 9275 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 9276 ** changeset (pChangeset) must remain valid until after the iterator is 9277 ** destroyed. 9278 ** 9279 ** Assuming the changeset blob was created by one of the 9280 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 9281 ** [sqlite3changeset_invert()] functions, all changes within the changeset 9282 ** that apply to a single table are grouped together. This means that when 9283 ** an application iterates through a changeset using an iterator created by 9284 ** this function, all changes that relate to a single table are visited 9285 ** consecutively. There is no chance that the iterator will visit a change 9286 ** the applies to table X, then one for table Y, and then later on visit 9287 ** another change for table X. 9288 */ 9289 SQLITE_API int sqlite3changeset_start( 9290 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 9291 int nChangeset, /* Size of changeset blob in bytes */ 9292 void *pChangeset /* Pointer to blob containing changeset */ 9293 ); 9294 9295 9296 /* 9297 ** CAPI3REF: Advance A Changeset Iterator 9298 ** 9299 ** This function may only be used with iterators created by function 9300 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 9301 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 9302 ** is returned and the call has no effect. 9303 ** 9304 ** Immediately after an iterator is created by sqlite3changeset_start(), it 9305 ** does not point to any change in the changeset. Assuming the changeset 9306 ** is not empty, the first call to this function advances the iterator to 9307 ** point to the first change in the changeset. Each subsequent call advances 9308 ** the iterator to point to the next change in the changeset (if any). If 9309 ** no error occurs and the iterator points to a valid change after a call 9310 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 9311 ** Otherwise, if all changes in the changeset have already been visited, 9312 ** SQLITE_DONE is returned. 9313 ** 9314 ** If an error occurs, an SQLite error code is returned. Possible error 9315 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 9316 ** SQLITE_NOMEM. 9317 */ 9318 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 9319 9320 /* 9321 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 9322 ** 9323 ** The pIter argument passed to this function may either be an iterator 9324 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9325 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9326 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 9327 ** is not the case, this function returns [SQLITE_MISUSE]. 9328 ** 9329 ** If argument pzTab is not NULL, then *pzTab is set to point to a 9330 ** nul-terminated utf-8 encoded string containing the name of the table 9331 ** affected by the current change. The buffer remains valid until either 9332 ** sqlite3changeset_next() is called on the iterator or until the 9333 ** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 9334 ** set to the number of columns in the table affected by the change. If 9335 ** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change 9336 ** is an indirect change, or false (0) otherwise. See the documentation for 9337 ** [sqlite3session_indirect()] for a description of direct and indirect 9338 ** changes. Finally, if pOp is not NULL, then *pOp is set to one of 9339 ** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 9340 ** type of change that the iterator currently points to. 9341 ** 9342 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 9343 ** SQLite error code is returned. The values of the output variables may not 9344 ** be trusted in this case. 9345 */ 9346 SQLITE_API int sqlite3changeset_op( 9347 sqlite3_changeset_iter *pIter, /* Iterator object */ 9348 const char **pzTab, /* OUT: Pointer to table name */ 9349 int *pnCol, /* OUT: Number of columns in table */ 9350 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 9351 int *pbIndirect /* OUT: True for an 'indirect' change */ 9352 ); 9353 9354 /* 9355 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 9356 ** 9357 ** For each modified table, a changeset includes the following: 9358 ** 9359 ** <ul> 9360 ** <li> The number of columns in the table, and 9361 ** <li> Which of those columns make up the tables PRIMARY KEY. 9362 ** </ul> 9363 ** 9364 ** This function is used to find which columns comprise the PRIMARY KEY of 9365 ** the table modified by the change that iterator pIter currently points to. 9366 ** If successful, *pabPK is set to point to an array of nCol entries, where 9367 ** nCol is the number of columns in the table. Elements of *pabPK are set to 9368 ** 0x01 if the corresponding column is part of the tables primary key, or 9369 ** 0x00 if it is not. 9370 ** 9371 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 9372 ** in the table. 9373 ** 9374 ** If this function is called when the iterator does not point to a valid 9375 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 9376 ** SQLITE_OK is returned and the output variables populated as described 9377 ** above. 9378 */ 9379 SQLITE_API int sqlite3changeset_pk( 9380 sqlite3_changeset_iter *pIter, /* Iterator object */ 9381 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 9382 int *pnCol /* OUT: Number of entries in output array */ 9383 ); 9384 9385 /* 9386 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 9387 ** 9388 ** The pIter argument passed to this function may either be an iterator 9389 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9390 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9391 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9392 ** Furthermore, it may only be called if the type of change that the iterator 9393 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 9394 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9395 ** 9396 ** Argument iVal must be greater than or equal to 0, and less than the number 9397 ** of columns in the table affected by the current change. Otherwise, 9398 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9399 ** 9400 ** If successful, this function sets *ppValue to point to a protected 9401 ** sqlite3_value object containing the iVal'th value from the vector of 9402 ** original row values stored as part of the UPDATE or DELETE change and 9403 ** returns SQLITE_OK. The name of the function comes from the fact that this 9404 ** is similar to the "old.*" columns available to update or delete triggers. 9405 ** 9406 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 9407 ** is returned and *ppValue is set to NULL. 9408 */ 9409 SQLITE_API int sqlite3changeset_old( 9410 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9411 int iVal, /* Column number */ 9412 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 9413 ); 9414 9415 /* 9416 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 9417 ** 9418 ** The pIter argument passed to this function may either be an iterator 9419 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9420 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9421 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 9422 ** Furthermore, it may only be called if the type of change that the iterator 9423 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 9424 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 9425 ** 9426 ** Argument iVal must be greater than or equal to 0, and less than the number 9427 ** of columns in the table affected by the current change. Otherwise, 9428 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9429 ** 9430 ** If successful, this function sets *ppValue to point to a protected 9431 ** sqlite3_value object containing the iVal'th value from the vector of 9432 ** new row values stored as part of the UPDATE or INSERT change and 9433 ** returns SQLITE_OK. If the change is an UPDATE and does not include 9434 ** a new value for the requested column, *ppValue is set to NULL and 9435 ** SQLITE_OK returned. The name of the function comes from the fact that 9436 ** this is similar to the "new.*" columns available to update or delete 9437 ** triggers. 9438 ** 9439 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 9440 ** is returned and *ppValue is set to NULL. 9441 */ 9442 SQLITE_API int sqlite3changeset_new( 9443 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9444 int iVal, /* Column number */ 9445 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 9446 ); 9447 9448 /* 9449 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 9450 ** 9451 ** This function should only be used with iterator objects passed to a 9452 ** conflict-handler callback by [sqlite3changeset_apply()] with either 9453 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 9454 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 9455 ** is set to NULL. 9456 ** 9457 ** Argument iVal must be greater than or equal to 0, and less than the number 9458 ** of columns in the table affected by the current change. Otherwise, 9459 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 9460 ** 9461 ** If successful, this function sets *ppValue to point to a protected 9462 ** sqlite3_value object containing the iVal'th value from the 9463 ** "conflicting row" associated with the current conflict-handler callback 9464 ** and returns SQLITE_OK. 9465 ** 9466 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 9467 ** is returned and *ppValue is set to NULL. 9468 */ 9469 SQLITE_API int sqlite3changeset_conflict( 9470 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9471 int iVal, /* Column number */ 9472 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 9473 ); 9474 9475 /* 9476 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 9477 ** 9478 ** This function may only be called with an iterator passed to an 9479 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 9480 ** it sets the output variable to the total number of known foreign key 9481 ** violations in the destination database and returns SQLITE_OK. 9482 ** 9483 ** In all other cases this function returns SQLITE_MISUSE. 9484 */ 9485 SQLITE_API int sqlite3changeset_fk_conflicts( 9486 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 9487 int *pnOut /* OUT: Number of FK violations */ 9488 ); 9489 9490 9491 /* 9492 ** CAPI3REF: Finalize A Changeset Iterator 9493 ** 9494 ** This function is used to finalize an iterator allocated with 9495 ** [sqlite3changeset_start()]. 9496 ** 9497 ** This function should only be called on iterators created using the 9498 ** [sqlite3changeset_start()] function. If an application calls this 9499 ** function with an iterator passed to a conflict-handler by 9500 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 9501 ** call has no effect. 9502 ** 9503 ** If an error was encountered within a call to an sqlite3changeset_xxx() 9504 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 9505 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 9506 ** to that error is returned by this function. Otherwise, SQLITE_OK is 9507 ** returned. This is to allow the following pattern (pseudo-code): 9508 ** 9509 ** sqlite3changeset_start(); 9510 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 9511 ** // Do something with change. 9512 ** } 9513 ** rc = sqlite3changeset_finalize(); 9514 ** if( rc!=SQLITE_OK ){ 9515 ** // An error has occurred 9516 ** } 9517 */ 9518 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 9519 9520 /* 9521 ** CAPI3REF: Invert A Changeset 9522 ** 9523 ** This function is used to "invert" a changeset object. Applying an inverted 9524 ** changeset to a database reverses the effects of applying the uninverted 9525 ** changeset. Specifically: 9526 ** 9527 ** <ul> 9528 ** <li> Each DELETE change is changed to an INSERT, and 9529 ** <li> Each INSERT change is changed to a DELETE, and 9530 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 9531 ** </ul> 9532 ** 9533 ** This function does not change the order in which changes appear within 9534 ** the changeset. It merely reverses the sense of each individual change. 9535 ** 9536 ** If successful, a pointer to a buffer containing the inverted changeset 9537 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 9538 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 9539 ** zeroed and an SQLite error code returned. 9540 ** 9541 ** It is the responsibility of the caller to eventually call sqlite3_free() 9542 ** on the *ppOut pointer to free the buffer allocation following a successful 9543 ** call to this function. 9544 ** 9545 ** WARNING/TODO: This function currently assumes that the input is a valid 9546 ** changeset. If it is not, the results are undefined. 9547 */ 9548 SQLITE_API int sqlite3changeset_invert( 9549 int nIn, const void *pIn, /* Input changeset */ 9550 int *pnOut, void **ppOut /* OUT: Inverse of input */ 9551 ); 9552 9553 /* 9554 ** CAPI3REF: Concatenate Two Changeset Objects 9555 ** 9556 ** This function is used to concatenate two changesets, A and B, into a 9557 ** single changeset. The result is a changeset equivalent to applying 9558 ** changeset A followed by changeset B. 9559 ** 9560 ** This function combines the two input changesets using an 9561 ** sqlite3_changegroup object. Calling it produces similar results as the 9562 ** following code fragment: 9563 ** 9564 ** sqlite3_changegroup *pGrp; 9565 ** rc = sqlite3_changegroup_new(&pGrp); 9566 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 9567 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 9568 ** if( rc==SQLITE_OK ){ 9569 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 9570 ** }else{ 9571 ** *ppOut = 0; 9572 ** *pnOut = 0; 9573 ** } 9574 ** 9575 ** Refer to the sqlite3_changegroup documentation below for details. 9576 */ 9577 SQLITE_API int sqlite3changeset_concat( 9578 int nA, /* Number of bytes in buffer pA */ 9579 void *pA, /* Pointer to buffer containing changeset A */ 9580 int nB, /* Number of bytes in buffer pB */ 9581 void *pB, /* Pointer to buffer containing changeset B */ 9582 int *pnOut, /* OUT: Number of bytes in output changeset */ 9583 void **ppOut /* OUT: Buffer containing output changeset */ 9584 ); 9585 9586 9587 /* 9588 ** CAPI3REF: Changegroup Handle 9589 */ 9590 typedef struct sqlite3_changegroup sqlite3_changegroup; 9591 9592 /* 9593 ** CAPI3REF: Create A New Changegroup Object 9594 ** 9595 ** An sqlite3_changegroup object is used to combine two or more changesets 9596 ** (or patchsets) into a single changeset (or patchset). A single changegroup 9597 ** object may combine changesets or patchsets, but not both. The output is 9598 ** always in the same format as the input. 9599 ** 9600 ** If successful, this function returns SQLITE_OK and populates (*pp) with 9601 ** a pointer to a new sqlite3_changegroup object before returning. The caller 9602 ** should eventually free the returned object using a call to 9603 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 9604 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 9605 ** 9606 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 9607 ** 9608 ** <ul> 9609 ** <li> It is created using a call to sqlite3changegroup_new(). 9610 ** 9611 ** <li> Zero or more changesets (or patchsets) are added to the object 9612 ** by calling sqlite3changegroup_add(). 9613 ** 9614 ** <li> The result of combining all input changesets together is obtained 9615 ** by the application via a call to sqlite3changegroup_output(). 9616 ** 9617 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 9618 ** </ul> 9619 ** 9620 ** Any number of calls to add() and output() may be made between the calls to 9621 ** new() and delete(), and in any order. 9622 ** 9623 ** As well as the regular sqlite3changegroup_add() and 9624 ** sqlite3changegroup_output() functions, also available are the streaming 9625 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 9626 */ 9627 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 9628 9629 /* 9630 ** CAPI3REF: Add A Changeset To A Changegroup 9631 ** 9632 ** Add all changes within the changeset (or patchset) in buffer pData (size 9633 ** nData bytes) to the changegroup. 9634 ** 9635 ** If the buffer contains a patchset, then all prior calls to this function 9636 ** on the same changegroup object must also have specified patchsets. Or, if 9637 ** the buffer contains a changeset, so must have the earlier calls to this 9638 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 9639 ** to the changegroup. 9640 ** 9641 ** Rows within the changeset and changegroup are identified by the values in 9642 ** their PRIMARY KEY columns. A change in the changeset is considered to 9643 ** apply to the same row as a change already present in the changegroup if 9644 ** the two rows have the same primary key. 9645 ** 9646 ** Changes to rows that do not already appear in the changegroup are 9647 ** simply copied into it. Or, if both the new changeset and the changegroup 9648 ** contain changes that apply to a single row, the final contents of the 9649 ** changegroup depends on the type of each change, as follows: 9650 ** 9651 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 9652 ** <tr><th style="white-space:pre">Existing Change </th> 9653 ** <th style="white-space:pre">New Change </th> 9654 ** <th>Output Change 9655 ** <tr><td>INSERT <td>INSERT <td> 9656 ** The new change is ignored. This case does not occur if the new 9657 ** changeset was recorded immediately after the changesets already 9658 ** added to the changegroup. 9659 ** <tr><td>INSERT <td>UPDATE <td> 9660 ** The INSERT change remains in the changegroup. The values in the 9661 ** INSERT change are modified as if the row was inserted by the 9662 ** existing change and then updated according to the new change. 9663 ** <tr><td>INSERT <td>DELETE <td> 9664 ** The existing INSERT is removed from the changegroup. The DELETE is 9665 ** not added. 9666 ** <tr><td>UPDATE <td>INSERT <td> 9667 ** The new change is ignored. This case does not occur if the new 9668 ** changeset was recorded immediately after the changesets already 9669 ** added to the changegroup. 9670 ** <tr><td>UPDATE <td>UPDATE <td> 9671 ** The existing UPDATE remains within the changegroup. It is amended 9672 ** so that the accompanying values are as if the row was updated once 9673 ** by the existing change and then again by the new change. 9674 ** <tr><td>UPDATE <td>DELETE <td> 9675 ** The existing UPDATE is replaced by the new DELETE within the 9676 ** changegroup. 9677 ** <tr><td>DELETE <td>INSERT <td> 9678 ** If one or more of the column values in the row inserted by the 9679 ** new change differ from those in the row deleted by the existing 9680 ** change, the existing DELETE is replaced by an UPDATE within the 9681 ** changegroup. Otherwise, if the inserted row is exactly the same 9682 ** as the deleted row, the existing DELETE is simply discarded. 9683 ** <tr><td>DELETE <td>UPDATE <td> 9684 ** The new change is ignored. This case does not occur if the new 9685 ** changeset was recorded immediately after the changesets already 9686 ** added to the changegroup. 9687 ** <tr><td>DELETE <td>DELETE <td> 9688 ** The new change is ignored. This case does not occur if the new 9689 ** changeset was recorded immediately after the changesets already 9690 ** added to the changegroup. 9691 ** </table> 9692 ** 9693 ** If the new changeset contains changes to a table that is already present 9694 ** in the changegroup, then the number of columns and the position of the 9695 ** primary key columns for the table must be consistent. If this is not the 9696 ** case, this function fails with SQLITE_SCHEMA. If the input changeset 9697 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 9698 ** returned. Or, if an out-of-memory condition occurs during processing, this 9699 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the 9700 ** final contents of the changegroup is undefined. 9701 ** 9702 ** If no error occurs, SQLITE_OK is returned. 9703 */ 9704 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 9705 9706 /* 9707 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 9708 ** 9709 ** Obtain a buffer containing a changeset (or patchset) representing the 9710 ** current contents of the changegroup. If the inputs to the changegroup 9711 ** were themselves changesets, the output is a changeset. Or, if the 9712 ** inputs were patchsets, the output is also a patchset. 9713 ** 9714 ** As with the output of the sqlite3session_changeset() and 9715 ** sqlite3session_patchset() functions, all changes related to a single 9716 ** table are grouped together in the output of this function. Tables appear 9717 ** in the same order as for the very first changeset added to the changegroup. 9718 ** If the second or subsequent changesets added to the changegroup contain 9719 ** changes for tables that do not appear in the first changeset, they are 9720 ** appended onto the end of the output changeset, again in the order in 9721 ** which they are first encountered. 9722 ** 9723 ** If an error occurs, an SQLite error code is returned and the output 9724 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 9725 ** is returned and the output variables are set to the size of and a 9726 ** pointer to the output buffer, respectively. In this case it is the 9727 ** responsibility of the caller to eventually free the buffer using a 9728 ** call to sqlite3_free(). 9729 */ 9730 SQLITE_API int sqlite3changegroup_output( 9731 sqlite3_changegroup*, 9732 int *pnData, /* OUT: Size of output buffer in bytes */ 9733 void **ppData /* OUT: Pointer to output buffer */ 9734 ); 9735 9736 /* 9737 ** CAPI3REF: Delete A Changegroup Object 9738 */ 9739 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 9740 9741 /* 9742 ** CAPI3REF: Apply A Changeset To A Database 9743 ** 9744 ** Apply a changeset to a database. This function attempts to update the 9745 ** "main" database attached to handle db with the changes found in the 9746 ** changeset passed via the second and third arguments. 9747 ** 9748 ** The fourth argument (xFilter) passed to this function is the "filter 9749 ** callback". If it is not NULL, then for each table affected by at least one 9750 ** change in the changeset, the filter callback is invoked with 9751 ** the table name as the second argument, and a copy of the context pointer 9752 ** passed as the sixth argument to this function as the first. If the "filter 9753 ** callback" returns zero, then no attempt is made to apply any changes to 9754 ** the table. Otherwise, if the return value is non-zero or the xFilter 9755 ** argument to this function is NULL, all changes related to the table are 9756 ** attempted. 9757 ** 9758 ** For each table that is not excluded by the filter callback, this function 9759 ** tests that the target database contains a compatible table. A table is 9760 ** considered compatible if all of the following are true: 9761 ** 9762 ** <ul> 9763 ** <li> The table has the same name as the name recorded in the 9764 ** changeset, and 9765 ** <li> The table has at least as many columns as recorded in the 9766 ** changeset, and 9767 ** <li> The table has primary key columns in the same position as 9768 ** recorded in the changeset. 9769 ** </ul> 9770 ** 9771 ** If there is no compatible table, it is not an error, but none of the 9772 ** changes associated with the table are applied. A warning message is issued 9773 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 9774 ** one such warning is issued for each table in the changeset. 9775 ** 9776 ** For each change for which there is a compatible table, an attempt is made 9777 ** to modify the table contents according to the UPDATE, INSERT or DELETE 9778 ** change. If a change cannot be applied cleanly, the conflict handler 9779 ** function passed as the fifth argument to sqlite3changeset_apply() may be 9780 ** invoked. A description of exactly when the conflict handler is invoked for 9781 ** each type of change is below. 9782 ** 9783 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 9784 ** of passing anything other than a valid function pointer as the xConflict 9785 ** argument are undefined. 9786 ** 9787 ** Each time the conflict handler function is invoked, it must return one 9788 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 9789 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 9790 ** if the second argument passed to the conflict handler is either 9791 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 9792 ** returns an illegal value, any changes already made are rolled back and 9793 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 9794 ** actions are taken by sqlite3changeset_apply() depending on the value 9795 ** returned by each invocation of the conflict-handler function. Refer to 9796 ** the documentation for the three 9797 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 9798 ** 9799 ** <dl> 9800 ** <dt>DELETE Changes<dd> 9801 ** For each DELETE change, this function checks if the target database 9802 ** contains a row with the same primary key value (or values) as the 9803 ** original row values stored in the changeset. If it does, and the values 9804 ** stored in all non-primary key columns also match the values stored in 9805 ** the changeset the row is deleted from the target database. 9806 ** 9807 ** If a row with matching primary key values is found, but one or more of 9808 ** the non-primary key fields contains a value different from the original 9809 ** row value stored in the changeset, the conflict-handler function is 9810 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 9811 ** database table has more columns than are recorded in the changeset, 9812 ** only the values of those non-primary key fields are compared against 9813 ** the current database contents - any trailing database table columns 9814 ** are ignored. 9815 ** 9816 ** If no row with matching primary key values is found in the database, 9817 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 9818 ** passed as the second argument. 9819 ** 9820 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 9821 ** (which can only happen if a foreign key constraint is violated), the 9822 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 9823 ** passed as the second argument. This includes the case where the DELETE 9824 ** operation is attempted because an earlier call to the conflict handler 9825 ** function returned [SQLITE_CHANGESET_REPLACE]. 9826 ** 9827 ** <dt>INSERT Changes<dd> 9828 ** For each INSERT change, an attempt is made to insert the new row into 9829 ** the database. If the changeset row contains fewer fields than the 9830 ** database table, the trailing fields are populated with their default 9831 ** values. 9832 ** 9833 ** If the attempt to insert the row fails because the database already 9834 ** contains a row with the same primary key values, the conflict handler 9835 ** function is invoked with the second argument set to 9836 ** [SQLITE_CHANGESET_CONFLICT]. 9837 ** 9838 ** If the attempt to insert the row fails because of some other constraint 9839 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 9840 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 9841 ** This includes the case where the INSERT operation is re-attempted because 9842 ** an earlier call to the conflict handler function returned 9843 ** [SQLITE_CHANGESET_REPLACE]. 9844 ** 9845 ** <dt>UPDATE Changes<dd> 9846 ** For each UPDATE change, this function checks if the target database 9847 ** contains a row with the same primary key value (or values) as the 9848 ** original row values stored in the changeset. If it does, and the values 9849 ** stored in all modified non-primary key columns also match the values 9850 ** stored in the changeset the row is updated within the target database. 9851 ** 9852 ** If a row with matching primary key values is found, but one or more of 9853 ** the modified non-primary key fields contains a value different from an 9854 ** original row value stored in the changeset, the conflict-handler function 9855 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 9856 ** UPDATE changes only contain values for non-primary key fields that are 9857 ** to be modified, only those fields need to match the original values to 9858 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 9859 ** 9860 ** If no row with matching primary key values is found in the database, 9861 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 9862 ** passed as the second argument. 9863 ** 9864 ** If the UPDATE operation is attempted, but SQLite returns 9865 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 9866 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 9867 ** This includes the case where the UPDATE operation is attempted after 9868 ** an earlier call to the conflict handler function returned 9869 ** [SQLITE_CHANGESET_REPLACE]. 9870 ** </dl> 9871 ** 9872 ** It is safe to execute SQL statements, including those that write to the 9873 ** table that the callback related to, from within the xConflict callback. 9874 ** This can be used to further customize the applications conflict 9875 ** resolution strategy. 9876 ** 9877 ** All changes made by this function are enclosed in a savepoint transaction. 9878 ** If any other error (aside from a constraint failure when attempting to 9879 ** write to the target database) occurs, then the savepoint transaction is 9880 ** rolled back, restoring the target database to its original state, and an 9881 ** SQLite error code returned. 9882 */ 9883 SQLITE_API int sqlite3changeset_apply( 9884 sqlite3 *db, /* Apply change to "main" db of this handle */ 9885 int nChangeset, /* Size of changeset in bytes */ 9886 void *pChangeset, /* Changeset blob */ 9887 int(*xFilter)( 9888 void *pCtx, /* Copy of sixth arg to _apply() */ 9889 const char *zTab /* Table name */ 9890 ), 9891 int(*xConflict)( 9892 void *pCtx, /* Copy of sixth arg to _apply() */ 9893 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 9894 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 9895 ), 9896 void *pCtx /* First argument passed to xConflict */ 9897 ); 9898 9899 /* 9900 ** CAPI3REF: Constants Passed To The Conflict Handler 9901 ** 9902 ** Values that may be passed as the second argument to a conflict-handler. 9903 ** 9904 ** <dl> 9905 ** <dt>SQLITE_CHANGESET_DATA<dd> 9906 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 9907 ** when processing a DELETE or UPDATE change if a row with the required 9908 ** PRIMARY KEY fields is present in the database, but one or more other 9909 ** (non primary-key) fields modified by the update do not contain the 9910 ** expected "before" values. 9911 ** 9912 ** The conflicting row, in this case, is the database row with the matching 9913 ** primary key. 9914 ** 9915 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 9916 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 9917 ** argument when processing a DELETE or UPDATE change if a row with the 9918 ** required PRIMARY KEY fields is not present in the database. 9919 ** 9920 ** There is no conflicting row in this case. The results of invoking the 9921 ** sqlite3changeset_conflict() API are undefined. 9922 ** 9923 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 9924 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 9925 ** handler while processing an INSERT change if the operation would result 9926 ** in duplicate primary key values. 9927 ** 9928 ** The conflicting row in this case is the database row with the matching 9929 ** primary key. 9930 ** 9931 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 9932 ** If foreign key handling is enabled, and applying a changeset leaves the 9933 ** database in a state containing foreign key violations, the conflict 9934 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 9935 ** exactly once before the changeset is committed. If the conflict handler 9936 ** returns CHANGESET_OMIT, the changes, including those that caused the 9937 ** foreign key constraint violation, are committed. Or, if it returns 9938 ** CHANGESET_ABORT, the changeset is rolled back. 9939 ** 9940 ** No current or conflicting row information is provided. The only function 9941 ** it is possible to call on the supplied sqlite3_changeset_iter handle 9942 ** is sqlite3changeset_fk_conflicts(). 9943 ** 9944 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 9945 ** If any other constraint violation occurs while applying a change (i.e. 9946 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 9947 ** invoked with CHANGESET_CONSTRAINT as the second argument. 9948 ** 9949 ** There is no conflicting row in this case. The results of invoking the 9950 ** sqlite3changeset_conflict() API are undefined. 9951 ** 9952 ** </dl> 9953 */ 9954 #define SQLITE_CHANGESET_DATA 1 9955 #define SQLITE_CHANGESET_NOTFOUND 2 9956 #define SQLITE_CHANGESET_CONFLICT 3 9957 #define SQLITE_CHANGESET_CONSTRAINT 4 9958 #define SQLITE_CHANGESET_FOREIGN_KEY 5 9959 9960 /* 9961 ** CAPI3REF: Constants Returned By The Conflict Handler 9962 ** 9963 ** A conflict handler callback must return one of the following three values. 9964 ** 9965 ** <dl> 9966 ** <dt>SQLITE_CHANGESET_OMIT<dd> 9967 ** If a conflict handler returns this value no special action is taken. The 9968 ** change that caused the conflict is not applied. The session module 9969 ** continues to the next change in the changeset. 9970 ** 9971 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 9972 ** This value may only be returned if the second argument to the conflict 9973 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 9974 ** is not the case, any changes applied so far are rolled back and the 9975 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 9976 ** 9977 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 9978 ** handler, then the conflicting row is either updated or deleted, depending 9979 ** on the type of change. 9980 ** 9981 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 9982 ** handler, then the conflicting row is removed from the database and a 9983 ** second attempt to apply the change is made. If this second attempt fails, 9984 ** the original row is restored to the database before continuing. 9985 ** 9986 ** <dt>SQLITE_CHANGESET_ABORT<dd> 9987 ** If this value is returned, any changes applied so far are rolled back 9988 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 9989 ** </dl> 9990 */ 9991 #define SQLITE_CHANGESET_OMIT 0 9992 #define SQLITE_CHANGESET_REPLACE 1 9993 #define SQLITE_CHANGESET_ABORT 2 9994 9995 /* 9996 ** CAPI3REF: Streaming Versions of API functions. 9997 ** 9998 ** The six streaming API xxx_strm() functions serve similar purposes to the 9999 ** corresponding non-streaming API functions: 10000 ** 10001 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 10002 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 10003 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 10004 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 10005 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 10006 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 10007 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 10008 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 10009 ** </table> 10010 ** 10011 ** Non-streaming functions that accept changesets (or patchsets) as input 10012 ** require that the entire changeset be stored in a single buffer in memory. 10013 ** Similarly, those that return a changeset or patchset do so by returning 10014 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 10015 ** Normally this is convenient. However, if an application running in a 10016 ** low-memory environment is required to handle very large changesets, the 10017 ** large contiguous memory allocations required can become onerous. 10018 ** 10019 ** In order to avoid this problem, instead of a single large buffer, input 10020 ** is passed to a streaming API functions by way of a callback function that 10021 ** the sessions module invokes to incrementally request input data as it is 10022 ** required. In all cases, a pair of API function parameters such as 10023 ** 10024 ** <pre> 10025 ** int nChangeset, 10026 ** void *pChangeset, 10027 ** </pre> 10028 ** 10029 ** Is replaced by: 10030 ** 10031 ** <pre> 10032 ** int (*xInput)(void *pIn, void *pData, int *pnData), 10033 ** void *pIn, 10034 ** </pre> 10035 ** 10036 ** Each time the xInput callback is invoked by the sessions module, the first 10037 ** argument passed is a copy of the supplied pIn context pointer. The second 10038 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 10039 ** error occurs the xInput method should copy up to (*pnData) bytes of data 10040 ** into the buffer and set (*pnData) to the actual number of bytes copied 10041 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 10042 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 10043 ** error code should be returned. In all cases, if an xInput callback returns 10044 ** an error, all processing is abandoned and the streaming API function 10045 ** returns a copy of the error code to the caller. 10046 ** 10047 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 10048 ** invoked by the sessions module at any point during the lifetime of the 10049 ** iterator. If such an xInput callback returns an error, the iterator enters 10050 ** an error state, whereby all subsequent calls to iterator functions 10051 ** immediately fail with the same error code as returned by xInput. 10052 ** 10053 ** Similarly, streaming API functions that return changesets (or patchsets) 10054 ** return them in chunks by way of a callback function instead of via a 10055 ** pointer to a single large buffer. In this case, a pair of parameters such 10056 ** as: 10057 ** 10058 ** <pre> 10059 ** int *pnChangeset, 10060 ** void **ppChangeset, 10061 ** </pre> 10062 ** 10063 ** Is replaced by: 10064 ** 10065 ** <pre> 10066 ** int (*xOutput)(void *pOut, const void *pData, int nData), 10067 ** void *pOut 10068 ** </pre> 10069 ** 10070 ** The xOutput callback is invoked zero or more times to return data to 10071 ** the application. The first parameter passed to each call is a copy of the 10072 ** pOut pointer supplied by the application. The second parameter, pData, 10073 ** points to a buffer nData bytes in size containing the chunk of output 10074 ** data being returned. If the xOutput callback successfully processes the 10075 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 10076 ** it should return some other SQLite error code. In this case processing 10077 ** is immediately abandoned and the streaming API function returns a copy 10078 ** of the xOutput error code to the application. 10079 ** 10080 ** The sessions module never invokes an xOutput callback with the third 10081 ** parameter set to a value less than or equal to zero. Other than this, 10082 ** no guarantees are made as to the size of the chunks of data returned. 10083 */ 10084 SQLITE_API int sqlite3changeset_apply_strm( 10085 sqlite3 *db, /* Apply change to "main" db of this handle */ 10086 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 10087 void *pIn, /* First arg for xInput */ 10088 int(*xFilter)( 10089 void *pCtx, /* Copy of sixth arg to _apply() */ 10090 const char *zTab /* Table name */ 10091 ), 10092 int(*xConflict)( 10093 void *pCtx, /* Copy of sixth arg to _apply() */ 10094 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10095 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10096 ), 10097 void *pCtx /* First argument passed to xConflict */ 10098 ); 10099 SQLITE_API int sqlite3changeset_concat_strm( 10100 int (*xInputA)(void *pIn, void *pData, int *pnData), 10101 void *pInA, 10102 int (*xInputB)(void *pIn, void *pData, int *pnData), 10103 void *pInB, 10104 int (*xOutput)(void *pOut, const void *pData, int nData), 10105 void *pOut 10106 ); 10107 SQLITE_API int sqlite3changeset_invert_strm( 10108 int (*xInput)(void *pIn, void *pData, int *pnData), 10109 void *pIn, 10110 int (*xOutput)(void *pOut, const void *pData, int nData), 10111 void *pOut 10112 ); 10113 SQLITE_API int sqlite3changeset_start_strm( 10114 sqlite3_changeset_iter **pp, 10115 int (*xInput)(void *pIn, void *pData, int *pnData), 10116 void *pIn 10117 ); 10118 SQLITE_API int sqlite3session_changeset_strm( 10119 sqlite3_session *pSession, 10120 int (*xOutput)(void *pOut, const void *pData, int nData), 10121 void *pOut 10122 ); 10123 SQLITE_API int sqlite3session_patchset_strm( 10124 sqlite3_session *pSession, 10125 int (*xOutput)(void *pOut, const void *pData, int nData), 10126 void *pOut 10127 ); 10128 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 10129 int (*xInput)(void *pIn, void *pData, int *pnData), 10130 void *pIn 10131 ); 10132 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 10133 int (*xOutput)(void *pOut, const void *pData, int nData), 10134 void *pOut 10135 ); 10136 10137 10138 /* 10139 ** Make sure we can call this stuff from C++. 10140 */ 10141 #ifdef __cplusplus 10142 } 10143 #endif 10144 10145 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 10146 10147 /******** End of sqlite3session.h *********/ 10148 /******** Begin file fts5.h *********/ 10149 /* 10150 ** 2014 May 31 10151 ** 10152 ** The author disclaims copyright to this source code. In place of 10153 ** a legal notice, here is a blessing: 10154 ** 10155 ** May you do good and not evil. 10156 ** May you find forgiveness for yourself and forgive others. 10157 ** May you share freely, never taking more than you give. 10158 ** 10159 ****************************************************************************** 10160 ** 10161 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 10162 ** FTS5 may be extended with: 10163 ** 10164 ** * custom tokenizers, and 10165 ** * custom auxiliary functions. 10166 */ 10167 10168 10169 #ifndef _FTS5_H 10170 #define _FTS5_H 10171 10172 10173 #ifdef __cplusplus 10174 extern "C" { 10175 #endif 10176 10177 /************************************************************************* 10178 ** CUSTOM AUXILIARY FUNCTIONS 10179 ** 10180 ** Virtual table implementations may overload SQL functions by implementing 10181 ** the sqlite3_module.xFindFunction() method. 10182 */ 10183 10184 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 10185 typedef struct Fts5Context Fts5Context; 10186 typedef struct Fts5PhraseIter Fts5PhraseIter; 10187 10188 typedef void (*fts5_extension_function)( 10189 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 10190 Fts5Context *pFts, /* First arg to pass to pApi functions */ 10191 sqlite3_context *pCtx, /* Context for returning result/error */ 10192 int nVal, /* Number of values in apVal[] array */ 10193 sqlite3_value **apVal /* Array of trailing arguments */ 10194 ); 10195 10196 struct Fts5PhraseIter { 10197 const unsigned char *a; 10198 const unsigned char *b; 10199 }; 10200 10201 /* 10202 ** EXTENSION API FUNCTIONS 10203 ** 10204 ** xUserData(pFts): 10205 ** Return a copy of the context pointer the extension function was 10206 ** registered with. 10207 ** 10208 ** xColumnTotalSize(pFts, iCol, pnToken): 10209 ** If parameter iCol is less than zero, set output variable *pnToken 10210 ** to the total number of tokens in the FTS5 table. Or, if iCol is 10211 ** non-negative but less than the number of columns in the table, return 10212 ** the total number of tokens in column iCol, considering all rows in 10213 ** the FTS5 table. 10214 ** 10215 ** If parameter iCol is greater than or equal to the number of columns 10216 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 10217 ** an OOM condition or IO error), an appropriate SQLite error code is 10218 ** returned. 10219 ** 10220 ** xColumnCount(pFts): 10221 ** Return the number of columns in the table. 10222 ** 10223 ** xColumnSize(pFts, iCol, pnToken): 10224 ** If parameter iCol is less than zero, set output variable *pnToken 10225 ** to the total number of tokens in the current row. Or, if iCol is 10226 ** non-negative but less than the number of columns in the table, set 10227 ** *pnToken to the number of tokens in column iCol of the current row. 10228 ** 10229 ** If parameter iCol is greater than or equal to the number of columns 10230 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 10231 ** an OOM condition or IO error), an appropriate SQLite error code is 10232 ** returned. 10233 ** 10234 ** This function may be quite inefficient if used with an FTS5 table 10235 ** created with the "columnsize=0" option. 10236 ** 10237 ** xColumnText: 10238 ** This function attempts to retrieve the text of column iCol of the 10239 ** current document. If successful, (*pz) is set to point to a buffer 10240 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 10241 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 10242 ** if an error occurs, an SQLite error code is returned and the final values 10243 ** of (*pz) and (*pn) are undefined. 10244 ** 10245 ** xPhraseCount: 10246 ** Returns the number of phrases in the current query expression. 10247 ** 10248 ** xPhraseSize: 10249 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 10250 ** are numbered starting from zero. 10251 ** 10252 ** xInstCount: 10253 ** Set *pnInst to the total number of occurrences of all phrases within 10254 ** the query within the current row. Return SQLITE_OK if successful, or 10255 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 10256 ** 10257 ** This API can be quite slow if used with an FTS5 table created with the 10258 ** "detail=none" or "detail=column" option. If the FTS5 table is created 10259 ** with either "detail=none" or "detail=column" and "content=" option 10260 ** (i.e. if it is a contentless table), then this API always returns 0. 10261 ** 10262 ** xInst: 10263 ** Query for the details of phrase match iIdx within the current row. 10264 ** Phrase matches are numbered starting from zero, so the iIdx argument 10265 ** should be greater than or equal to zero and smaller than the value 10266 ** output by xInstCount(). 10267 ** 10268 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 10269 ** to the column in which it occurs and *piOff the token offset of the 10270 ** first token of the phrase. The exception is if the table was created 10271 ** with the offsets=0 option specified. In this case *piOff is always 10272 ** set to -1. 10273 ** 10274 ** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 10275 ** if an error occurs. 10276 ** 10277 ** This API can be quite slow if used with an FTS5 table created with the 10278 ** "detail=none" or "detail=column" option. 10279 ** 10280 ** xRowid: 10281 ** Returns the rowid of the current row. 10282 ** 10283 ** xTokenize: 10284 ** Tokenize text using the tokenizer belonging to the FTS5 table. 10285 ** 10286 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 10287 ** This API function is used to query the FTS table for phrase iPhrase 10288 ** of the current query. Specifically, a query equivalent to: 10289 ** 10290 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 10291 ** 10292 ** with $p set to a phrase equivalent to the phrase iPhrase of the 10293 ** current query is executed. Any column filter that applies to 10294 ** phrase iPhrase of the current query is included in $p. For each 10295 ** row visited, the callback function passed as the fourth argument 10296 ** is invoked. The context and API objects passed to the callback 10297 ** function may be used to access the properties of each matched row. 10298 ** Invoking Api.xUserData() returns a copy of the pointer passed as 10299 ** the third argument to pUserData. 10300 ** 10301 ** If the callback function returns any value other than SQLITE_OK, the 10302 ** query is abandoned and the xQueryPhrase function returns immediately. 10303 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 10304 ** Otherwise, the error code is propagated upwards. 10305 ** 10306 ** If the query runs to completion without incident, SQLITE_OK is returned. 10307 ** Or, if some error occurs before the query completes or is aborted by 10308 ** the callback, an SQLite error code is returned. 10309 ** 10310 ** 10311 ** xSetAuxdata(pFts5, pAux, xDelete) 10312 ** 10313 ** Save the pointer passed as the second argument as the extension functions 10314 ** "auxiliary data". The pointer may then be retrieved by the current or any 10315 ** future invocation of the same fts5 extension function made as part of 10316 ** of the same MATCH query using the xGetAuxdata() API. 10317 ** 10318 ** Each extension function is allocated a single auxiliary data slot for 10319 ** each FTS query (MATCH expression). If the extension function is invoked 10320 ** more than once for a single FTS query, then all invocations share a 10321 ** single auxiliary data context. 10322 ** 10323 ** If there is already an auxiliary data pointer when this function is 10324 ** invoked, then it is replaced by the new pointer. If an xDelete callback 10325 ** was specified along with the original pointer, it is invoked at this 10326 ** point. 10327 ** 10328 ** The xDelete callback, if one is specified, is also invoked on the 10329 ** auxiliary data pointer after the FTS5 query has finished. 10330 ** 10331 ** If an error (e.g. an OOM condition) occurs within this function, an 10332 ** the auxiliary data is set to NULL and an error code returned. If the 10333 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 10334 ** pointer before returning. 10335 ** 10336 ** 10337 ** xGetAuxdata(pFts5, bClear) 10338 ** 10339 ** Returns the current auxiliary data pointer for the fts5 extension 10340 ** function. See the xSetAuxdata() method for details. 10341 ** 10342 ** If the bClear argument is non-zero, then the auxiliary data is cleared 10343 ** (set to NULL) before this function returns. In this case the xDelete, 10344 ** if any, is not invoked. 10345 ** 10346 ** 10347 ** xRowCount(pFts5, pnRow) 10348 ** 10349 ** This function is used to retrieve the total number of rows in the table. 10350 ** In other words, the same value that would be returned by: 10351 ** 10352 ** SELECT count(*) FROM ftstable; 10353 ** 10354 ** xPhraseFirst() 10355 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 10356 ** method, to iterate through all instances of a single query phrase within 10357 ** the current row. This is the same information as is accessible via the 10358 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 10359 ** to use, this API may be faster under some circumstances. To iterate 10360 ** through instances of phrase iPhrase, use the following code: 10361 ** 10362 ** Fts5PhraseIter iter; 10363 ** int iCol, iOff; 10364 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 10365 ** iCol>=0; 10366 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 10367 ** ){ 10368 ** // An instance of phrase iPhrase at offset iOff of column iCol 10369 ** } 10370 ** 10371 ** The Fts5PhraseIter structure is defined above. Applications should not 10372 ** modify this structure directly - it should only be used as shown above 10373 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 10374 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 10375 ** 10376 ** This API can be quite slow if used with an FTS5 table created with the 10377 ** "detail=none" or "detail=column" option. If the FTS5 table is created 10378 ** with either "detail=none" or "detail=column" and "content=" option 10379 ** (i.e. if it is a contentless table), then this API always iterates 10380 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 10381 ** 10382 ** xPhraseNext() 10383 ** See xPhraseFirst above. 10384 ** 10385 ** xPhraseFirstColumn() 10386 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 10387 ** and xPhraseNext() APIs described above. The difference is that instead 10388 ** of iterating through all instances of a phrase in the current row, these 10389 ** APIs are used to iterate through the set of columns in the current row 10390 ** that contain one or more instances of a specified phrase. For example: 10391 ** 10392 ** Fts5PhraseIter iter; 10393 ** int iCol; 10394 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 10395 ** iCol>=0; 10396 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 10397 ** ){ 10398 ** // Column iCol contains at least one instance of phrase iPhrase 10399 ** } 10400 ** 10401 ** This API can be quite slow if used with an FTS5 table created with the 10402 ** "detail=none" option. If the FTS5 table is created with either 10403 ** "detail=none" "content=" option (i.e. if it is a contentless table), 10404 ** then this API always iterates through an empty set (all calls to 10405 ** xPhraseFirstColumn() set iCol to -1). 10406 ** 10407 ** The information accessed using this API and its companion 10408 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 10409 ** (or xInst/xInstCount). The chief advantage of this API is that it is 10410 ** significantly more efficient than those alternatives when used with 10411 ** "detail=column" tables. 10412 ** 10413 ** xPhraseNextColumn() 10414 ** See xPhraseFirstColumn above. 10415 */ 10416 struct Fts5ExtensionApi { 10417 int iVersion; /* Currently always set to 3 */ 10418 10419 void *(*xUserData)(Fts5Context*); 10420 10421 int (*xColumnCount)(Fts5Context*); 10422 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 10423 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 10424 10425 int (*xTokenize)(Fts5Context*, 10426 const char *pText, int nText, /* Text to tokenize */ 10427 void *pCtx, /* Context passed to xToken() */ 10428 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 10429 ); 10430 10431 int (*xPhraseCount)(Fts5Context*); 10432 int (*xPhraseSize)(Fts5Context*, int iPhrase); 10433 10434 int (*xInstCount)(Fts5Context*, int *pnInst); 10435 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 10436 10437 sqlite3_int64 (*xRowid)(Fts5Context*); 10438 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 10439 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 10440 10441 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 10442 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 10443 ); 10444 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 10445 void *(*xGetAuxdata)(Fts5Context*, int bClear); 10446 10447 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 10448 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 10449 10450 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 10451 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 10452 }; 10453 10454 /* 10455 ** CUSTOM AUXILIARY FUNCTIONS 10456 *************************************************************************/ 10457 10458 /************************************************************************* 10459 ** CUSTOM TOKENIZERS 10460 ** 10461 ** Applications may also register custom tokenizer types. A tokenizer 10462 ** is registered by providing fts5 with a populated instance of the 10463 ** following structure. All structure methods must be defined, setting 10464 ** any member of the fts5_tokenizer struct to NULL leads to undefined 10465 ** behaviour. The structure methods are expected to function as follows: 10466 ** 10467 ** xCreate: 10468 ** This function is used to allocate and initialize a tokenizer instance. 10469 ** A tokenizer instance is required to actually tokenize text. 10470 ** 10471 ** The first argument passed to this function is a copy of the (void*) 10472 ** pointer provided by the application when the fts5_tokenizer object 10473 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 10474 ** The second and third arguments are an array of nul-terminated strings 10475 ** containing the tokenizer arguments, if any, specified following the 10476 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 10477 ** to create the FTS5 table. 10478 ** 10479 ** The final argument is an output variable. If successful, (*ppOut) 10480 ** should be set to point to the new tokenizer handle and SQLITE_OK 10481 ** returned. If an error occurs, some value other than SQLITE_OK should 10482 ** be returned. In this case, fts5 assumes that the final value of *ppOut 10483 ** is undefined. 10484 ** 10485 ** xDelete: 10486 ** This function is invoked to delete a tokenizer handle previously 10487 ** allocated using xCreate(). Fts5 guarantees that this function will 10488 ** be invoked exactly once for each successful call to xCreate(). 10489 ** 10490 ** xTokenize: 10491 ** This function is expected to tokenize the nText byte string indicated 10492 ** by argument pText. pText may or may not be nul-terminated. The first 10493 ** argument passed to this function is a pointer to an Fts5Tokenizer object 10494 ** returned by an earlier call to xCreate(). 10495 ** 10496 ** The second argument indicates the reason that FTS5 is requesting 10497 ** tokenization of the supplied text. This is always one of the following 10498 ** four values: 10499 ** 10500 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 10501 ** or removed from the FTS table. The tokenizer is being invoked to 10502 ** determine the set of tokens to add to (or delete from) the 10503 ** FTS index. 10504 ** 10505 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 10506 ** against the FTS index. The tokenizer is being called to tokenize 10507 ** a bareword or quoted string specified as part of the query. 10508 ** 10509 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 10510 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 10511 ** followed by a "*" character, indicating that the last token 10512 ** returned by the tokenizer will be treated as a token prefix. 10513 ** 10514 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 10515 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 10516 ** function. Or an fts5_api.xColumnSize() request made by the same 10517 ** on a columnsize=0 database. 10518 ** </ul> 10519 ** 10520 ** For each token in the input string, the supplied callback xToken() must 10521 ** be invoked. The first argument to it should be a copy of the pointer 10522 ** passed as the second argument to xTokenize(). The third and fourth 10523 ** arguments are a pointer to a buffer containing the token text, and the 10524 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 10525 ** of the first byte of and first byte immediately following the text from 10526 ** which the token is derived within the input. 10527 ** 10528 ** The second argument passed to the xToken() callback ("tflags") should 10529 ** normally be set to 0. The exception is if the tokenizer supports 10530 ** synonyms. In this case see the discussion below for details. 10531 ** 10532 ** FTS5 assumes the xToken() callback is invoked for each token in the 10533 ** order that they occur within the input text. 10534 ** 10535 ** If an xToken() callback returns any value other than SQLITE_OK, then 10536 ** the tokenization should be abandoned and the xTokenize() method should 10537 ** immediately return a copy of the xToken() return value. Or, if the 10538 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 10539 ** if an error occurs with the xTokenize() implementation itself, it 10540 ** may abandon the tokenization and return any error code other than 10541 ** SQLITE_OK or SQLITE_DONE. 10542 ** 10543 ** SYNONYM SUPPORT 10544 ** 10545 ** Custom tokenizers may also support synonyms. Consider a case in which a 10546 ** user wishes to query for a phrase such as "first place". Using the 10547 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 10548 ** of "first place" within the document set, but not alternative forms 10549 ** such as "1st place". In some applications, it would be better to match 10550 ** all instances of "first place" or "1st place" regardless of which form 10551 ** the user specified in the MATCH query text. 10552 ** 10553 ** There are several ways to approach this in FTS5: 10554 ** 10555 ** <ol><li> By mapping all synonyms to a single token. In this case, the 10556 ** In the above example, this means that the tokenizer returns the 10557 ** same token for inputs "first" and "1st". Say that token is in 10558 ** fact "first", so that when the user inserts the document "I won 10559 ** 1st place" entries are added to the index for tokens "i", "won", 10560 ** "first" and "place". If the user then queries for '1st + place', 10561 ** the tokenizer substitutes "first" for "1st" and the query works 10562 ** as expected. 10563 ** 10564 ** <li> By adding multiple synonyms for a single term to the FTS index. 10565 ** In this case, when tokenizing query text, the tokenizer may 10566 ** provide multiple synonyms for a single term within the document. 10567 ** FTS5 then queries the index for each synonym individually. For 10568 ** example, faced with the query: 10569 ** 10570 ** <codeblock> 10571 ** ... MATCH 'first place'</codeblock> 10572 ** 10573 ** the tokenizer offers both "1st" and "first" as synonyms for the 10574 ** first token in the MATCH query and FTS5 effectively runs a query 10575 ** similar to: 10576 ** 10577 ** <codeblock> 10578 ** ... MATCH '(first OR 1st) place'</codeblock> 10579 ** 10580 ** except that, for the purposes of auxiliary functions, the query 10581 ** still appears to contain just two phrases - "(first OR 1st)" 10582 ** being treated as a single phrase. 10583 ** 10584 ** <li> By adding multiple synonyms for a single term to the FTS index. 10585 ** Using this method, when tokenizing document text, the tokenizer 10586 ** provides multiple synonyms for each token. So that when a 10587 ** document such as "I won first place" is tokenized, entries are 10588 ** added to the FTS index for "i", "won", "first", "1st" and 10589 ** "place". 10590 ** 10591 ** This way, even if the tokenizer does not provide synonyms 10592 ** when tokenizing query text (it should not - to do would be 10593 ** inefficient), it doesn't matter if the user queries for 10594 ** 'first + place' or '1st + place', as there are entires in the 10595 ** FTS index corresponding to both forms of the first token. 10596 ** </ol> 10597 ** 10598 ** Whether it is parsing document or query text, any call to xToken that 10599 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 10600 ** is considered to supply a synonym for the previous token. For example, 10601 ** when parsing the document "I won first place", a tokenizer that supports 10602 ** synonyms would call xToken() 5 times, as follows: 10603 ** 10604 ** <codeblock> 10605 ** xToken(pCtx, 0, "i", 1, 0, 1); 10606 ** xToken(pCtx, 0, "won", 3, 2, 5); 10607 ** xToken(pCtx, 0, "first", 5, 6, 11); 10608 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 10609 ** xToken(pCtx, 0, "place", 5, 12, 17); 10610 **</codeblock> 10611 ** 10612 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 10613 ** xToken() is called. Multiple synonyms may be specified for a single token 10614 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 10615 ** There is no limit to the number of synonyms that may be provided for a 10616 ** single token. 10617 ** 10618 ** In many cases, method (1) above is the best approach. It does not add 10619 ** extra data to the FTS index or require FTS5 to query for multiple terms, 10620 ** so it is efficient in terms of disk space and query speed. However, it 10621 ** does not support prefix queries very well. If, as suggested above, the 10622 ** token "first" is subsituted for "1st" by the tokenizer, then the query: 10623 ** 10624 ** <codeblock> 10625 ** ... MATCH '1s*'</codeblock> 10626 ** 10627 ** will not match documents that contain the token "1st" (as the tokenizer 10628 ** will probably not map "1s" to any prefix of "first"). 10629 ** 10630 ** For full prefix support, method (3) may be preferred. In this case, 10631 ** because the index contains entries for both "first" and "1st", prefix 10632 ** queries such as 'fi*' or '1s*' will match correctly. However, because 10633 ** extra entries are added to the FTS index, this method uses more space 10634 ** within the database. 10635 ** 10636 ** Method (2) offers a midpoint between (1) and (3). Using this method, 10637 ** a query such as '1s*' will match documents that contain the literal 10638 ** token "1st", but not "first" (assuming the tokenizer is not able to 10639 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 10640 ** will match against "1st" and "first". This method does not require 10641 ** extra disk space, as no extra entries are added to the FTS index. 10642 ** On the other hand, it may require more CPU cycles to run MATCH queries, 10643 ** as separate queries of the FTS index are required for each synonym. 10644 ** 10645 ** When using methods (2) or (3), it is important that the tokenizer only 10646 ** provide synonyms when tokenizing document text (method (2)) or query 10647 ** text (method (3)), not both. Doing so will not cause any errors, but is 10648 ** inefficient. 10649 */ 10650 typedef struct Fts5Tokenizer Fts5Tokenizer; 10651 typedef struct fts5_tokenizer fts5_tokenizer; 10652 struct fts5_tokenizer { 10653 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 10654 void (*xDelete)(Fts5Tokenizer*); 10655 int (*xTokenize)(Fts5Tokenizer*, 10656 void *pCtx, 10657 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 10658 const char *pText, int nText, 10659 int (*xToken)( 10660 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 10661 int tflags, /* Mask of FTS5_TOKEN_* flags */ 10662 const char *pToken, /* Pointer to buffer containing token */ 10663 int nToken, /* Size of token in bytes */ 10664 int iStart, /* Byte offset of token within input text */ 10665 int iEnd /* Byte offset of end of token within input text */ 10666 ) 10667 ); 10668 }; 10669 10670 /* Flags that may be passed as the third argument to xTokenize() */ 10671 #define FTS5_TOKENIZE_QUERY 0x0001 10672 #define FTS5_TOKENIZE_PREFIX 0x0002 10673 #define FTS5_TOKENIZE_DOCUMENT 0x0004 10674 #define FTS5_TOKENIZE_AUX 0x0008 10675 10676 /* Flags that may be passed by the tokenizer implementation back to FTS5 10677 ** as the third argument to the supplied xToken callback. */ 10678 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 10679 10680 /* 10681 ** END OF CUSTOM TOKENIZERS 10682 *************************************************************************/ 10683 10684 /************************************************************************* 10685 ** FTS5 EXTENSION REGISTRATION API 10686 */ 10687 typedef struct fts5_api fts5_api; 10688 struct fts5_api { 10689 int iVersion; /* Currently always set to 2 */ 10690 10691 /* Create a new tokenizer */ 10692 int (*xCreateTokenizer)( 10693 fts5_api *pApi, 10694 const char *zName, 10695 void *pContext, 10696 fts5_tokenizer *pTokenizer, 10697 void (*xDestroy)(void*) 10698 ); 10699 10700 /* Find an existing tokenizer */ 10701 int (*xFindTokenizer)( 10702 fts5_api *pApi, 10703 const char *zName, 10704 void **ppContext, 10705 fts5_tokenizer *pTokenizer 10706 ); 10707 10708 /* Create a new auxiliary function */ 10709 int (*xCreateFunction)( 10710 fts5_api *pApi, 10711 const char *zName, 10712 void *pContext, 10713 fts5_extension_function xFunction, 10714 void (*xDestroy)(void*) 10715 ); 10716 }; 10717 10718 /* 10719 ** END OF REGISTRATION API 10720 *************************************************************************/ 10721 10722 #ifdef __cplusplus 10723 } /* end of the 'extern "C"' block */ 10724 #endif 10725 10726 #endif /* _FTS5_H */ 10727 10728 /******** End of fts5.h *********/ 10729 #else // USE_LIBSQLITE3 10730 // If users really want to link against the system sqlite3 we 10731 // need to make this file a noop. 10732 #endif