SQLite

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is responsible for
** generating the code that loops through a table looking for applicable
** rows.  Indices are selected and used to speed the search when doing
** so is applicable.  Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
**
** $Id: where.c,v 1.365 2009/01/24 09:56:15 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Trace output macros
*/
#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)

      if( pTerm==0 ) break;
      wsFlags |= WHERE_COLUMN_EQ;
      if( pTerm->eOperator & WO_IN ){
        Expr *pExpr = pTerm->pExpr;
        wsFlags |= WHERE_COLUMN_IN;
        if( pExpr->pSelect!=0 ){
          inMultiplier *= 25;
        }else if( pExpr->pList ){
          inMultiplier *= pExpr->pList->nExpr + 1;
        }
      }
    }
    nRow = pProbe->aiRowEst[i] * inMultiplier;
    cost = nRow * estLog(inMultiplier);
    nEq = i;

# 2008 September 1
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# $Id: in4.test,v 1.3 2009/01/24 09:56:15 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

do_test in4-1.1 {
  execsql {
    CREATE TABLE t1(a, b);

  execsql { SELECT b FROM t2 WHERE a IN ('1', '2') }
} {one two}

do_test in4-2.8 {
  execsql { SELECT b FROM t2 WHERE a IN ('', '0.0.0', '2') }
} {two}

# The following block of tests test expressions of the form:
#
#    <expr> IN ()
#
# i.e. IN expressions with a literal empty set. 
# 
# This has led to crashes on more than one occasion. Test case in4-3.2 
# was added in reponse to a bug reported on the mailing list on 11/7/2008.

# See also tickets #3602 and #185.
#
do_test in4-3.1 {
  execsql {
    DROP TABLE IF EXISTS t1;
    DROP TABLE IF EXISTS t2;
    CREATE TABLE t1(x, id);
    CREATE TABLE t2(x, id);
    INSERT INTO t1 VALUES(NULL, NULL);

  }
} {}
do_test in4-3.2 {
  execsql {
    SELECT x FROM t1 WHERE id IN () AND x IN (SELECT x FROM t2 WHERE id=1)
  }
} {}
do_test in4-3.3 {
  execsql {
    CREATE TABLE t3(x, y, z);
    CREATE INDEX t3i1 ON t3(x, y);
    INSERT INTO t3 VALUES(1, 1, 1);
    INSERT INTO t3 VALUES(10, 10, 10);
  }
  execsql { SELECT * FROM t3 WHERE x IN () }
} {}
do_test in4-3.4 {
  execsql { SELECT * FROM t3 WHERE x = 10 AND y IN () }
} {}
do_test in4-3.5 {
  execsql { SELECT * FROM t3 WHERE x IN () AND y = 10 }
} {}
do_test in4-3.6 {
  execsql { SELECT * FROM t3 WHERE x IN () OR x = 10 }
} {10 10 10}
do_test in4-3.7 {
  execsql { SELECT * FROM t3 WHERE y IN () }
} {}
do_test in4-3.8 {
  execsql { SELECT x IN() AS a FROM t3 WHERE a }
} {}
do_test in4-3.9 {
  execsql { SELECT x IN() AS a FROM t3 WHERE NOT a }
} {0 0}
do_test in4-3.10 {
  execsql { SELECT * FROM t3 WHERE oid IN () }
} {}
do_test in4-3.11 {
  execsql { SELECT * FROM t3 WHERE x IN (1, 2) OR y IN ()}
} {1 1 1}
do_test in4-3.12 {
  execsql { SELECT * FROM t3 WHERE x IN (1, 2) AND y IN ()}
} {}

finish_test