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Do not flatten subqueries that are part of a compound SELECT and which

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have both an ORDER BY and a LIMIT clause.  Ticket #2339. (CVS 3932)

FossilOrigin-Name: 9600a998043c6dd1d5ecb03d1ee9a9273910243d
This commit is contained in:
drh
2007-05-06 20:04:24 +00:00
parent 83852acc44
commit ad91c6cd40
4 changed files with 112 additions and 9 deletions
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9
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 1.340 2007/05/04 13:15:56 drh Exp $
** $Id: select.c,v 1.341 2007/05/06 20:04:25 drh Exp $
*/
#include "sqliteInt.h"
@@ -2128,6 +2128,10 @@ static void substSelect(Select *p, int iTable, ExprList *pEList){
**
** (14) The subquery does not use OFFSET
**
** (15) The outer query is not part of a compound select or the
** subquery does not have both an ORDER BY and a LIMIT clause.
** (See ticket #2339)
**
** In this routine, the "p" parameter is a pointer to the outer query.
** The subquery is p->pSrc->a[iFrom]. isAgg is true if the outer query
** uses aggregates and subqueryIsAgg is true if the subquery uses aggregates.
@@ -2172,6 +2176,9 @@ static int flattenSubquery(
** and (14). */
if( pSub->pLimit && p->pLimit ) return 0; /* Restriction (13) */
if( pSub->pOffset ) return 0; /* Restriction (14) */
if( p->pRightmost && pSub->pLimit && pSub->pOrderBy ){
return 0; /* Restriction (15) */
}
if( pSubSrc->nSrc==0 ) return 0; /* Restriction (7) */
if( (pSub->isDistinct || pSub->pLimit)
&& (pSrc->nSrc>1 || isAgg) ){ /* Restrictions (4)(5)(8)(9) */