SQLite

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is reponsible 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 1.232 2006/11/06 15:10:05 drh Exp $
*/
#include "sqliteInt.h"

/*
** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
*/
#define BMS  (sizeof(Bitmask)*8)

          ok = 0;
        }
      }
    }while( !ok && (sOr.a[j++].flags & TERM_COPIED)!=0 && j<sOr.nTerm );
    if( ok ){
      ExprList *pList = 0;
      Expr *pNew, *pDup;
      Expr *pLeft = 0;
      for(i=sOr.nTerm-1, pOrTerm=sOr.a; i>=0 && ok; i--, pOrTerm++){
        if( (pOrTerm->flags & TERM_OR_OK)==0 ) continue;
        pDup = sqlite3ExprDup(pOrTerm->pExpr->pRight);
        pList = sqlite3ExprListAppend(pList, pDup, 0);
        pLeft = pOrTerm->pExpr->pLeft;
      }
      assert( pLeft!=0 );
      pDup = sqlite3ExprDup(pLeft);




      pNew = sqlite3Expr(TK_IN, pDup, 0, 0);
      if( pNew ){
        int idxNew;
        transferJoinMarkings(pNew, pExpr);
        pNew->pList = pList;
        idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC);
        exprAnalyze(pSrc, pMaskSet, pWC, idxNew);

#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the use of indices in WHERE clauses
# based on recent changes to the optimizer.
#
# $Id: where2.test,v 1.10 2006/11/06 15:10:06 drh Exp $

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

# Build some test data
#
do_test where2-1.0 {

      SELECT w FROM tx
       WHERE x IN (SELECT x FROM t1 WHERE +w BETWEEN 200 AND 300)
         AND y IN (SELECT y FROM t1 WHERE +w BETWEEN 10 AND 20)
         AND z IN (SELECT z FROM t1 WHERE +w BETWEEN 10 AND 20)
    }
  } {}
}  

# Make sure WHERE clauses of the form A=1 AND (B=2 OR B=3) are optimized
# when we have an index on A and B.
#
ifcapable or_opt {
  do_test where2-9.1 {
    execsql {
      BEGIN;
      CREATE TABLE t10(a,b,c);
      INSERT INTO t10 VALUES(1,1,1);
      INSERT INTO t10 VALUES(1,2,2);
      INSERT INTO t10 VALUES(1,3,3);
    }
    for {set i 4} {$i<=1000} {incr i} {
      execsql {INSERT INTO t10 VALUES(1,$i,$i)}
    }
    execsql {
      CREATE INDEX i10 ON t10(a,b);
      COMMIT;
      SELECT count(*) FROM t10;
    }
  } 1000
  do_test where2-9.2 {
    count {
      SELECT * FROM t10 WHERE a=1 AND (b=2 OR b=3)
    }
  } {1 2 2 1 3 3 7}
}

finish_test