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Defer deleting Table objects associated with flattened subqueries until

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all code has been generated, in case some expression node still references
the Table object.  Ticket #3346. (CVS 5650)

FossilOrigin-Name: d04d70336727a0db959c672e6c22cdaa0505dce5
This commit is contained in:
drh
2008-09-01 15:52:10 +00:00
parent 865d4d4290
commit 588a9a1a1c
8 changed files with 83 additions and 20 deletions
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29
src/select.c
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@@ -12,7 +12,7 @@
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.471 2008/08/26 12:56:14 drh Exp $
** $Id: select.c,v 1.472 2008/09/01 15:52:11 drh Exp $
*/
#include "sqliteInt.h"
@@ -2427,6 +2427,9 @@ static void substSelect(
int iTable, /* Table to be replaced */
ExprList *pEList /* Substitute values */
){
SrcList *pSrc;
struct SrcList_item *pItem;
int i;
if( !p ) return;
substExprList(db, p->pEList, iTable, pEList);
substExprList(db, p->pGroupBy, iTable, pEList);
@@ -2434,6 +2437,12 @@ static void substSelect(
substExpr(db, p->pHaving, iTable, pEList);
substExpr(db, p->pWhere, iTable, pEList);
substSelect(db, p->pPrior, iTable, pEList);
pSrc = p->pSrc;
if( pSrc ){
for(i=pSrc->nSrc, pItem=pSrc->a; i>0; i--, pItem++){
substSelect(db, pItem->pSelect, iTable, pEList);
}
}
}
#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */
@@ -2718,17 +2727,31 @@ static int flattenSubquery(
** elements we are now copying in.
*/
if( pSrc ){
Table *pTabToDel;
pSubitem = &pSrc->a[iFrom];
nSubSrc = pSubSrc->nSrc;
jointype = pSubitem->jointype;
sqlite3DeleteTable(pSubitem->pTab);
sqlite3DbFree(db, pSubitem->zDatabase);
sqlite3DbFree(db, pSubitem->zName);
sqlite3DbFree(db, pSubitem->zAlias);
pSubitem->pTab = 0;
pSubitem->zDatabase = 0;
pSubitem->zName = 0;
pSubitem->zAlias = 0;
/* If the FROM element is a subquery, defer deleting the Table
** object associated with that subquery until code generation is
** complete, since there may still exist Expr.pTab entires that
** refer to the subquery even after flattening. Ticket #3346.
*/
if( (pTabToDel = pSubitem->pTab)!=0 ){
if( pTabToDel->nRef==1 ){
pTabToDel->pNextZombie = pParse->pZombieTab;
pParse->pZombieTab = pTabToDel;
}else{
pTabToDel->nRef--;
}
}
pSubitem->pTab = 0;
}
if( nSubSrc!=1 || !pSrc ){
int extra = nSubSrc - 1;