diff options
Diffstat (limited to 'src/wherecode.c')
-rw-r--r-- | src/wherecode.c | 58 |
1 files changed, 45 insertions, 13 deletions
diff --git a/src/wherecode.c b/src/wherecode.c index a620a5ac0..30624be8a 100644 --- a/src/wherecode.c +++ b/src/wherecode.c @@ -460,6 +460,39 @@ static void updateRangeAffinityStr( } } +/* +** The pOrderBy->a[].u.x.iOrderByCol values might be incorrect because +** columns might have been rearranged in the result set. This routine +** fixes them up. +** +** pEList is the new result set. The pEList->a[].u.x.iOrderByCol values +** contain the *old* locations of each expression. This is a temporary +** use of u.x.iOrderByCol, not its intended use. The caller must reset +** u.x.iOrderByCol back to zero for all entries in pEList before the +** caller returns. +** +** This routine changes pOrderBy->a[].u.x.iOrderByCol values from +** pEList->a[N].u.x.iOrderByCol into N+1. (The "+1" is because of the 1-based +** indexing used by iOrderByCol.) Or if no match, iOrderByCol is set to zero. +*/ +static void adjustOrderByCol(ExprList *pOrderBy, ExprList *pEList){ + int i, j; + if( pOrderBy==0 ) return; + for(i=0; i<pOrderBy->nExpr; i++){ + int t = pOrderBy->a[i].u.x.iOrderByCol; + if( t==0 ) continue; + for(j=0; j<pEList->nExpr; j++){ + if( pEList->a[j].u.x.iOrderByCol==t ){ + pOrderBy->a[i].u.x.iOrderByCol = j+1; + break; + } + } + if( j>=pEList->nExpr ){ + pOrderBy->a[i].u.x.iOrderByCol = 0; + } + } +} + /* ** pX is an expression of the form: (vector) IN (SELECT ...) @@ -522,7 +555,8 @@ static Expr *removeUnindexableInClauseTerms( iField = pLoop->aLTerm[i]->u.x.iField - 1; if( pOrigRhs->a[iField].pExpr==0 ) continue; /* Duplicate PK column */ pRhs = sqlite3ExprListAppend(pParse, pRhs, pOrigRhs->a[iField].pExpr); - pOrigRhs->a[iField].pExpr = 0; + pOrigRhs->a[iField].pExpr = 0; + if( pRhs ) pRhs->a[pRhs->nExpr-1].u.x.iOrderByCol = iField+1; if( pOrigLhs ){ assert( pOrigLhs->a[iField].pExpr!=0 ); pLhs = sqlite3ExprListAppend(pParse,pLhs,pOrigLhs->a[iField].pExpr); @@ -545,18 +579,16 @@ static Expr *removeUnindexableInClauseTerms( sqlite3ExprDelete(db, pNew->pLeft); pNew->pLeft = p; } - if( pSelect->pOrderBy ){ - /* If the SELECT statement has an ORDER BY clause, zero the - ** iOrderByCol variables. These are set to non-zero when an - ** ORDER BY term exactly matches one of the terms of the - ** result-set. Since the result-set of the SELECT statement may - ** have been modified or reordered, these variables are no longer - ** set correctly. Since setting them is just an optimization, - ** it's easiest just to zero them here. */ - ExprList *pOrderBy = pSelect->pOrderBy; - for(i=0; i<pOrderBy->nExpr; i++){ - pOrderBy->a[i].u.x.iOrderByCol = 0; - } + + /* If either the ORDER BY clause or the GROUP BY clause contains + ** references to result-set columns, those references might now be + ** obsolete. So fix them up. + */ + assert( pRhs!=0 || db->mallocFailed ); + if( pRhs ){ + adjustOrderByCol(pSelect->pOrderBy, pRhs); + adjustOrderByCol(pSelect->pGroupBy, pRhs); + for(i=0; i<pRhs->nExpr; i++) pRhs->a[i].u.x.iOrderByCol = 0; } #if 0 |