github.com/jdgcs/sqlite3@v1.12.1-0.20210908114423-bc5f96e4dd51/testdata/tcl/func5.test (about)

     1  # 2013-11-21
     2  #
     3  # The author disclaims copyright to this source code.  In place of
     4  # a legal notice, here is a blessing:
     5  #
     6  #    May you do good and not evil.
     7  #    May you find forgiveness for yourself and forgive others.
     8  #    May you share freely, never taking more than you give.
     9  #
    10  #*************************************************************************
    11  #
    12  # Testing of function factoring and the SQLITE_DETERMINISTIC flag.
    13  #
    14  set testdir [file dirname $argv0]
    15  source $testdir/tester.tcl
    16  
    17  # Verify that constant string expressions that get factored into initializing
    18  # code are not reused between function parameters and other values in the
    19  # VDBE program, as the function might have changed the encoding.
    20  #
    21  do_execsql_test func5-1.1 {
    22    PRAGMA encoding=UTF16le;
    23    CREATE TABLE t1(x,a,b,c);
    24    INSERT INTO t1 VALUES(1,'ab','cd',1);
    25    INSERT INTO t1 VALUES(2,'gh','ef',5);
    26    INSERT INTO t1 VALUES(3,'pqr','fuzzy',99);
    27    INSERT INTO t1 VALUES(4,'abcdefg','xy',22);
    28    INSERT INTO t1 VALUES(5,'shoe','mayer',2953);
    29    SELECT x FROM t1 WHERE c=instr('abcdefg',b) OR a='abcdefg' ORDER BY +x;
    30  } {2 4}
    31  do_execsql_test func5-1.2 {
    32    SELECT x FROM t1 WHERE a='abcdefg' OR c=instr('abcdefg',b) ORDER BY +x;
    33  } {2 4}
    34  
    35  # Verify that SQLITE_DETERMINISTIC functions get factored out of the
    36  # evaluation loop whereas non-deterministic functions do not.  counter1()
    37  # is marked as non-deterministic and so is not factored out of the loop,
    38  # and it really is non-deterministic, returning a different result each
    39  # time.  But counter2() is marked as deterministic, so it does get factored
    40  # out of the loop.  counter2() has the same implementation as counter1(),
    41  # returning a different result on each invocation, but because it is 
    42  # only invoked once outside of the loop, it appears to return the same
    43  # result multiple times.
    44  #
    45  do_execsql_test func5-2.1 {
    46    CREATE TABLE t2(x,y);
    47    INSERT INTO t2 VALUES(1,2),(3,4),(5,6),(7,8);
    48    SELECT x, y FROM t2 WHERE x+5=5+x ORDER BY +x;
    49  } {1 2 3 4 5 6 7 8}
    50  sqlite3_create_function db
    51  do_execsql_test func5-2.2 {
    52    SELECT x, y FROM t2
    53     WHERE x+counter1('hello')=counter1('hello')+x
    54     ORDER BY +x;
    55  } {}
    56  set cvalue [db one {SELECT counter2('hello')+1}]
    57  do_execsql_test func5-2.3 {
    58    SELECT x, y FROM t2
    59     WHERE x+counter2('hello')=$cvalue+x
    60     ORDER BY +x;
    61  } {1 2 3 4 5 6 7 8}
    62  
    63  
    64  finish_test