gitlab.com/CoiaPrant/sqlite3@v1.19.1/testdata/tcl/in2.test (about)

     1  # 2007 May 12
     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  # This file tests a special case in the b-tree code that can be
    12  # hit by the "IN" operator (or EXISTS, NOT IN, etc.).
    13  #
    14  # $Id: in2.test,v 1.3 2008/07/12 14:52:20 drh Exp $
    15  
    16  set testdir [file dirname $argv0]
    17  source $testdir/tester.tcl
    18  
    19  do_test in2-1 {
    20    execsql {
    21      CREATE TABLE a(i INTEGER PRIMARY KEY, a);
    22    }
    23  } {}
    24  
    25  set ::N 2000
    26  
    27  do_test in2-2 {
    28    db transaction {
    29      for {set ::ii 0} {$::ii < $::N} {incr ::ii} {
    30        execsql {INSERT INTO a VALUES($::ii, $::ii)}
    31      }
    32      execsql {INSERT INTO a VALUES(4000, '')}
    33  
    34      for {set ::ii 0} {$::ii < $::N} {incr ::ii} {
    35        set ::t [format "x%04d" $ii]
    36        execsql {INSERT INTO a VALUES(NULL, $::t)}
    37      }
    38    }
    39  } {}
    40  
    41  # Each iteration of this loop builds a slightly different b-tree to
    42  # evaluate the "IN (...)" operator in the SQL statement. The contents
    43  # of the b-tree are (in sorted order):
    44  #
    45  #     $::ii integers.
    46  #     a string of zero length.
    47  #     $::N short strings.
    48  #
    49  # Records are inserted in sorted order.
    50  #
    51  # The string of zero-length is stored in a b-tree cell with 3 bytes
    52  # of payload. Moving this cell from a leaf node to a internal node 
    53  # during b-tree balancing was causing an assertion failure. 
    54  #
    55  # This bug only applied to b-trees generated to evaluate IN (..) 
    56  # clauses, as it is impossible for persistent b-trees (SQL tables + 
    57  # indices) to contain cells smaller than 4 bytes.
    58  #
    59  for {set ::ii 3} {$::ii < $::N} {incr ::ii} {
    60    do_test in2-$::ii {
    61      execsql {
    62        SELECT 1 IN (SELECT a FROM a WHERE (i < $::ii) OR (i >= $::N))
    63      }
    64    } {1}
    65  }
    66  
    67  finish_test