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Overview
Comment:Partial fix for a problem with LEFT OUTER JOIN. It used to be that the test for the right-hand table not matching the left table occurred after all ON, USING, WHERE clause processing. The test should occur after ON and USING clauses are checked but before the WHERE clause is check. This fix works as long as the total number of "AND" separated terms in the ON, USING, and WHERE clause does not exceed 32. To do: make this work for any number of terms and add test cases. that (CVS 639)
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Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: 8b6574cfa86daaae910f8f3ee3c4723a21fb9e53
User & Date: drh 2002-06-24 22:01:58
Context
2002-06-25
01:09
Added support for the "sqlite_temp_master" table. Increased the version number to 2.5.2. (CVS 640) check-in: 9c1432bf user: drh tags: trunk
2002-06-24
22:01
Partial fix for a problem with LEFT OUTER JOIN. It used to be that the test for the right-hand table not matching the left table occurred after all ON, USING, WHERE clause processing. The test should occur after ON and USING clauses are checked but before the WHERE clause is check. This fix works as long as the total number of "AND" separated terms in the ON, USING, and WHERE clause does not exceed 32. To do: make this work for any number of terms and add test cases. that (CVS 639) check-in: 8b6574cf user: drh tags: trunk
12:20
Fix a VDBE stack leak in LEFT OUTER JOIN. Fix a bug in the code generator for JOIN ... USING(...). (CVS 638) check-in: d861489e user: drh tags: trunk
Changes
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Changes to src/select.c.

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**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.98 2002/06/24 12:20:23 drh Exp $
*/
#include "sqliteInt.h"

/*
** Allocate a new Select structure and return a pointer to that
** structure.
*/
................................................................................
  pE1b = sqliteExpr(TK_ID, 0, 0, &dummy);
  dummy.z = pTab2->zName;
  dummy.n = strlen(dummy.z);
  pE2b = sqliteExpr(TK_ID, 0, 0, &dummy);
  pE1c = sqliteExpr(TK_DOT, pE1b, pE1a, 0);
  pE2c = sqliteExpr(TK_DOT, pE2b, pE2a, 0);
  pE = sqliteExpr(TK_EQ, pE1c, pE2c, 0);

  if( *ppExpr ){
    *ppExpr = sqliteExpr(TK_AND, *ppExpr, pE, 0);
  }else{
    *ppExpr = pE;
  }
}
















/*
** This routine processes the join information for a SELECT statement.
** ON and USING clauses are converted into extra terms of the WHERE clause.
** NATURAL joins also create extra WHERE clause terms.
**
** This routine returns the number of errors encountered.
................................................................................
      return 1;
    }

    /* Add the ON clause to the end of the WHERE clause, connected by
    ** and AND operator.
    */
    if( pTerm->pOn ){

      if( p->pWhere==0 ){
        p->pWhere = pTerm->pOn;
      }else{
        p->pWhere = sqliteExpr(TK_AND, p->pWhere, pTerm->pOn, 0);
      }
      pTerm->pOn = 0;
    }







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**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.99 2002/06/24 22:01:58 drh Exp $
*/
#include "sqliteInt.h"

/*
** Allocate a new Select structure and return a pointer to that
** structure.
*/
................................................................................
  pE1b = sqliteExpr(TK_ID, 0, 0, &dummy);
  dummy.z = pTab2->zName;
  dummy.n = strlen(dummy.z);
  pE2b = sqliteExpr(TK_ID, 0, 0, &dummy);
  pE1c = sqliteExpr(TK_DOT, pE1b, pE1a, 0);
  pE2c = sqliteExpr(TK_DOT, pE2b, pE2a, 0);
  pE = sqliteExpr(TK_EQ, pE1c, pE2c, 0);
  pE->isJoinExpr = 1;
  if( *ppExpr ){
    *ppExpr = sqliteExpr(TK_AND, *ppExpr, pE, 0);
  }else{
    *ppExpr = pE;
  }
}

/*
** Set the Expr.isJoinExpr flag on all terms of the given expression.
**
** The Expr.isJoinExpr flag is used at on terms of an expression to tell
** the LEFT OUTER JOIN processing logic that this term is part of the
** join restriction and not a part of the more general WHERE clause.
*/
static void setJoinExpr(Expr *p){
  while( p ){
    p->isJoinExpr = 1;
    setJoinExpr(p->pLeft);
    p = p->pRight;
  } 
}

/*
** This routine processes the join information for a SELECT statement.
** ON and USING clauses are converted into extra terms of the WHERE clause.
** NATURAL joins also create extra WHERE clause terms.
**
** This routine returns the number of errors encountered.
................................................................................
      return 1;
    }

    /* Add the ON clause to the end of the WHERE clause, connected by
    ** and AND operator.
    */
    if( pTerm->pOn ){
      setJoinExpr(pTerm->pOn);
      if( p->pWhere==0 ){
        p->pWhere = pTerm->pOn;
      }else{
        p->pWhere = sqliteExpr(TK_AND, p->pWhere, pTerm->pOn, 0);
      }
      pTerm->pOn = 0;
    }

Changes to src/sqliteInt.h.

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**    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.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.129 2002/06/22 02:33:39 drh Exp $
*/
#include "sqlite.h"
#include "hash.h"
#include "vdbe.h"
#include "parse.h"
#include "btree.h"
#include <stdio.h>
................................................................................
**
** The Expr.pSelect field points to a SELECT statement.  The SELECT might
** be the right operand of an IN operator.  Or, if a scalar SELECT appears
** in an expression the opcode is TK_SELECT and Expr.pSelect is the only
** operand.
*/
struct Expr {
  u16 op;                /* Operation performed by this node */
  u8 dataType;           /* Either SQLITE_SO_TEXT or SQLITE_SO_NUM */

  Expr *pLeft, *pRight;  /* Left and right subnodes */
  ExprList *pList;       /* A list of expressions used as function arguments
                         ** or in "<expr> IN (<expr-list)" */
  Token token;           /* An operand token */
  Token span;            /* Complete text of the expression */
  int iTable, iColumn;   /* When op==TK_COLUMN, then this expr node means the
                         ** iColumn-th field of the iTable-th table. */







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**    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.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.130 2002/06/24 22:01:58 drh Exp $
*/
#include "sqlite.h"
#include "hash.h"
#include "vdbe.h"
#include "parse.h"
#include "btree.h"
#include <stdio.h>
................................................................................
**
** The Expr.pSelect field points to a SELECT statement.  The SELECT might
** be the right operand of an IN operator.  Or, if a scalar SELECT appears
** in an expression the opcode is TK_SELECT and Expr.pSelect is the only
** operand.
*/
struct Expr {
  u8 op;                 /* Operation performed by this node */
  u8 dataType;           /* Either SQLITE_SO_TEXT or SQLITE_SO_NUM */
  u8 isJoinExpr;         /* Origina is the ON or USING phrase of a join */
  Expr *pLeft, *pRight;  /* Left and right subnodes */
  ExprList *pList;       /* A list of expressions used as function arguments
                         ** or in "<expr> IN (<expr-list)" */
  Token token;           /* An operand token */
  Token span;            /* Complete text of the expression */
  int iTable, iColumn;   /* When op==TK_COLUMN, then this expr node means the
                         ** iColumn-th field of the iTable-th table. */

Changes to src/where.c.

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**    May you share freely, never taking more than you give.
**
*************************************************************************
** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  Also found here are subroutines
** to generate VDBE code to evaluate expressions.
**
** $Id: where.c,v 1.54 2002/06/24 12:20:23 drh Exp $
*/
#include "sqliteInt.h"

/*
** The query generator uses an array of instances of this structure to
** help it analyze the subexpressions of the WHERE clause.  Each WHERE
** clause subexpression is separated from the others by an AND operator.
................................................................................

    /* Insert code to test every subexpression that can be completely
    ** computed using the current set of tables.
    */
    for(j=0; j<nExpr; j++){
      if( aExpr[j].p==0 ) continue;
      if( (aExpr[j].prereqAll & loopMask)!=aExpr[j].prereqAll ) continue;

      if( haveKey ){
        haveKey = 0;
        sqliteVdbeAddOp(v, OP_MoveTo, base+idx, 0);
      }
      sqliteExprIfFalse(pParse, aExpr[j].p, cont, 1);
      aExpr[j].p = 0;
    }
................................................................................
    /* For a LEFT OUTER JOIN, generate code that will record the fact that
    ** at least one row of the right table has matched the left table.  
    */
    if( pLevel->iLeftJoin ){
      pLevel->top = sqliteVdbeCurrentAddr(v);
      sqliteVdbeAddOp(v, OP_Integer, 1, 0);
      sqliteVdbeAddOp(v, OP_MemStore, pLevel->iLeftJoin, 1);










    }
  }
  pWInfo->iContinue = cont;
  if( pushKey && !haveKey ){
    sqliteVdbeAddOp(v, OP_Recno, base, 0);
  }
  sqliteFree(aOrder);







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**    May you share freely, never taking more than you give.
**
*************************************************************************
** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  Also found here are subroutines
** to generate VDBE code to evaluate expressions.
**
** $Id: where.c,v 1.55 2002/06/24 22:01:59 drh Exp $
*/
#include "sqliteInt.h"

/*
** The query generator uses an array of instances of this structure to
** help it analyze the subexpressions of the WHERE clause.  Each WHERE
** clause subexpression is separated from the others by an AND operator.
................................................................................

    /* Insert code to test every subexpression that can be completely
    ** computed using the current set of tables.
    */
    for(j=0; j<nExpr; j++){
      if( aExpr[j].p==0 ) continue;
      if( (aExpr[j].prereqAll & loopMask)!=aExpr[j].prereqAll ) continue;
      if( pLevel->iLeftJoin && aExpr[j].p->isJoinExpr==0 ) continue;
      if( haveKey ){
        haveKey = 0;
        sqliteVdbeAddOp(v, OP_MoveTo, base+idx, 0);
      }
      sqliteExprIfFalse(pParse, aExpr[j].p, cont, 1);
      aExpr[j].p = 0;
    }
................................................................................
    /* For a LEFT OUTER JOIN, generate code that will record the fact that
    ** at least one row of the right table has matched the left table.  
    */
    if( pLevel->iLeftJoin ){
      pLevel->top = sqliteVdbeCurrentAddr(v);
      sqliteVdbeAddOp(v, OP_Integer, 1, 0);
      sqliteVdbeAddOp(v, OP_MemStore, pLevel->iLeftJoin, 1);
      for(j=0; j<nExpr; j++){
        if( aExpr[j].p==0 ) continue;
        if( (aExpr[j].prereqAll & loopMask)!=aExpr[j].prereqAll ) continue;
        if( haveKey ){
          haveKey = 0;
          sqliteVdbeAddOp(v, OP_MoveTo, base+idx, 0);
        }
        sqliteExprIfFalse(pParse, aExpr[j].p, cont, 1);
        aExpr[j].p = 0;
      }
    }
  }
  pWInfo->iContinue = cont;
  if( pushKey && !haveKey ){
    sqliteVdbeAddOp(v, OP_Recno, base, 0);
  }
  sqliteFree(aOrder);