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Use the WITH clause to help resolve names for SELECT statements on the left

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of a compound query.  Proposed fix for ticket [31a19d11b97088296a].

FossilOrigin-Name: 67bfd59d9087a987f15f6148efa1ff104983e1fb
This commit is contained in:
drh
2014-02-09 18:02:09 +00:00
parent fa46bfbbc5
commit d227a291b2
7 changed files with 67 additions and 54 deletions
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62
src/select.c
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@@ -109,6 +109,14 @@ void sqlite3SelectDelete(sqlite3 *db, Select *p){
}
}
/*
** Return a pointer to the right-most SELECT statement in a compound.
*/
static Select *findRightmost(Select *p){
while( p->pNext ) p = p->pNext;
return p;
}
/*
** Given 1 to 3 identifiers preceding the JOIN keyword, determine the
** type of join. Return an integer constant that expresses that type
@@ -1877,7 +1885,9 @@ static void generateWithRecursiveQuery(
p->pOrderBy = 0;
/* Store the results of the setup-query in Queue. */
pSetup->pNext = 0;
rc = sqlite3Select(pParse, pSetup, &destQueue);
pSetup->pNext = p;
if( rc ) goto end_of_recursive_query;
/* Find the next row in the Queue and output that row */
@@ -1982,8 +1992,6 @@ static int multiSelect(
assert( (p->selFlags & SF_Recursive)==0 || p->op==TK_ALL || p->op==TK_UNION );
db = pParse->db;
pPrior = p->pPrior;
assert( pPrior->pRightmost!=pPrior );
assert( pPrior->pRightmost==p->pRightmost );
dest = *pDest;
if( pPrior->pOrderBy ){
sqlite3ErrorMsg(pParse,"ORDER BY clause should come after %s not before",
@@ -2091,12 +2099,10 @@ static int multiSelect(
testcase( p->op==TK_EXCEPT );
testcase( p->op==TK_UNION );
priorOp = SRT_Union;
if( dest.eDest==priorOp && ALWAYS(!p->pLimit &&!p->pOffset) ){
if( dest.eDest==priorOp ){
/* We can reuse a temporary table generated by a SELECT to our
** right.
*/
assert( p->pRightmost!=p ); /* Can only happen for leftward elements
** of a 3-way or more compound */
assert( p->pLimit==0 ); /* Not allowed on leftward elements */
assert( p->pOffset==0 ); /* Not allowed on leftward elements */
unionTab = dest.iSDParm;
@@ -2109,7 +2115,7 @@ static int multiSelect(
addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, unionTab, 0);
assert( p->addrOpenEphm[0] == -1 );
p->addrOpenEphm[0] = addr;
p->pRightmost->selFlags |= SF_UsesEphemeral;
findRightmost(p)->selFlags |= SF_UsesEphemeral;
assert( p->pEList );
}
@@ -2198,7 +2204,7 @@ static int multiSelect(
addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab1, 0);
assert( p->addrOpenEphm[0] == -1 );
p->addrOpenEphm[0] = addr;
p->pRightmost->selFlags |= SF_UsesEphemeral;
findRightmost(p)->selFlags |= SF_UsesEphemeral;
assert( p->pEList );
/* Code the SELECTs to our left into temporary table "tab1".
@@ -2277,7 +2283,7 @@ static int multiSelect(
CollSeq **apColl; /* For looping through pKeyInfo->aColl[] */
int nCol; /* Number of columns in result set */
assert( p->pRightmost==p );
assert( p->pNext==0 );
nCol = p->pEList->nExpr;
pKeyInfo = sqlite3KeyInfoAlloc(db, nCol, 1);
if( !pKeyInfo ){
@@ -2693,6 +2699,7 @@ static int multiSelectOrderBy(
/* Separate the left and the right query from one another
*/
p->pPrior = 0;
pPrior->pNext = 0;
sqlite3ResolveOrderGroupBy(pParse, p, p->pOrderBy, "ORDER");
if( pPrior->pPrior==0 ){
sqlite3ResolveOrderGroupBy(pParse, pPrior, pPrior->pOrderBy, "ORDER");
@@ -2858,6 +2865,7 @@ static int multiSelectOrderBy(
sqlite3SelectDelete(db, p->pPrior);
}
p->pPrior = pPrior;
pPrior->pNext = p;
/*** TBD: Insert subroutine calls to close cursors on incomplete
**** subqueries ****/
@@ -3123,7 +3131,7 @@ 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 ){
if( (p->selFlags & SF_Compound)!=0 && pSub->pLimit ){
return 0; /* Restriction (15) */
}
if( pSubSrc->nSrc==0 ) return 0; /* Restriction (7) */
@@ -3274,14 +3282,14 @@ static int flattenSubquery(
p->pOrderBy = pOrderBy;
p->pSrc = pSrc;
p->op = TK_ALL;
p->pRightmost = 0;
if( pNew==0 ){
pNew = pPrior;
p->pPrior = pPrior;
}else{
pNew->pPrior = pPrior;
pNew->pRightmost = 0;
if( pPrior ) pPrior->pNext = pNew;
pNew->pNext = p;
p->pPrior = pNew;
}
p->pPrior = pNew;
if( db->mallocFailed ) return 1;
}
@@ -3807,9 +3815,10 @@ static int withExpand(
*/
static void selectPopWith(Walker *pWalker, Select *p){
Parse *pParse = pWalker->pParse;
if( p->pWith ){
assert( pParse->pWith==p->pWith );
pParse->pWith = p->pWith->pOuter;
With *pWith = findRightmost(p)->pWith;
if( pWith!=0 ){
assert( pParse->pWith==pWith );
pParse->pWith = pWith->pOuter;
}
}
#else
@@ -3859,7 +3868,7 @@ static int selectExpander(Walker *pWalker, Select *p){
}
pTabList = p->pSrc;
pEList = p->pEList;
sqlite3WithPush(pParse, p->pWith, 0);
sqlite3WithPush(pParse, findRightmost(p)->pWith, 0);
/* Make sure cursor numbers have been assigned to all entries in
** the FROM clause of the SELECT statement.
@@ -4603,21 +4612,6 @@ int sqlite3Select(
/* If there is are a sequence of queries, do the earlier ones first.
*/
if( p->pPrior ){
if( p->pRightmost==0 ){
Select *pLoop, *pRight = 0;
int cnt = 0;
int mxSelect;
for(pLoop=p; pLoop; pLoop=pLoop->pPrior, cnt++){
pLoop->pRightmost = p;
pLoop->pNext = pRight;
pRight = pLoop;
}
mxSelect = db->aLimit[SQLITE_LIMIT_COMPOUND_SELECT];
if( mxSelect && cnt>mxSelect ){
sqlite3ErrorMsg(pParse, "too many terms in compound SELECT");
goto select_end;
}
}
rc = multiSelect(pParse, p, pDest);
explainSetInteger(pParse->iSelectId, iRestoreSelectId);
return rc;
@@ -5279,10 +5273,6 @@ void sqlite3ExplainSelect(Vdbe *pVdbe, Select *p){
sqlite3ExplainPrintf(pVdbe, "(null-select)");
return;
}
while( p->pPrior ){
p->pPrior->pNext = p;
p = p->pPrior;
}
sqlite3ExplainPush(pVdbe);
while( p ){
explainOneSelect(pVdbe, p);