diff options
Diffstat (limited to 'lib/libsqlite3/src/select.c')
| -rw-r--r-- | lib/libsqlite3/src/select.c | 244 |
1 files changed, 188 insertions, 56 deletions
diff --git a/lib/libsqlite3/src/select.c b/lib/libsqlite3/src/select.c index a90877dc612..f3f14909639 100644 --- a/lib/libsqlite3/src/select.c +++ b/lib/libsqlite3/src/select.c @@ -55,7 +55,7 @@ Select *sqlite3SelectNew( ExprList *pGroupBy, /* the GROUP BY clause */ Expr *pHaving, /* the HAVING clause */ ExprList *pOrderBy, /* the ORDER BY clause */ - int isDistinct, /* true if the DISTINCT keyword is present */ + u16 selFlags, /* Flag parameters, such as SF_Distinct */ Expr *pLimit, /* LIMIT value. NULL means not used */ Expr *pOffset /* OFFSET value. NULL means no offset */ ){ @@ -79,7 +79,7 @@ Select *sqlite3SelectNew( pNew->pGroupBy = pGroupBy; pNew->pHaving = pHaving; pNew->pOrderBy = pOrderBy; - pNew->selFlags = isDistinct ? SF_Distinct : 0; + pNew->selFlags = selFlags; pNew->op = TK_SELECT; pNew->pLimit = pLimit; pNew->pOffset = pOffset; @@ -1336,8 +1336,6 @@ static int selectColumnsFromExprList( /* Get an appropriate name for the column */ p = sqlite3ExprSkipCollate(pEList->a[i].pExpr); - assert( p->pRight==0 || ExprHasProperty(p->pRight, EP_IntValue) - || p->pRight->u.zToken==0 || p->pRight->u.zToken[0]!=0 ); if( (zName = pEList->a[i].zName)!=0 ){ /* If the column contains an "AS <name>" phrase, use <name> as the name */ zName = sqlite3DbStrDup(db, zName); @@ -1375,6 +1373,9 @@ static int selectColumnsFromExprList( for(j=cnt=0; j<i; j++){ if( sqlite3StrICmp(aCol[j].zName, zName)==0 ){ char *zNewName; + int k; + for(k=nName-1; k>1 && sqlite3Isdigit(zName[k]); k--){} + if( zName[k]==':' ) nName = k; zName[nName] = 0; zNewName = sqlite3MPrintf(db, "%s:%d", zName, ++cnt); sqlite3DbFree(db, zName); @@ -1706,6 +1707,8 @@ static int multiSelect( int addr = 0; int nLimit; assert( !pPrior->pLimit ); + pPrior->iLimit = p->iLimit; + pPrior->iOffset = p->iOffset; pPrior->pLimit = p->pLimit; pPrior->pOffset = p->pOffset; explainSetInteger(iSub1, pParse->iNextSelectId); @@ -2363,7 +2366,8 @@ static int multiSelectOrderBy( }else{ int nExpr = p->pEList->nExpr; assert( nOrderBy>=nExpr || db->mallocFailed ); - regPrev = sqlite3GetTempRange(pParse, nExpr+1); + regPrev = pParse->nMem+1; + pParse->nMem += nExpr+1; sqlite3VdbeAddOp2(v, OP_Integer, 0, regPrev); pKeyDup = sqlite3DbMallocZero(db, sizeof(*pKeyDup) + nExpr*(sizeof(CollSeq*)+1) ); @@ -2545,12 +2549,6 @@ static int multiSelectOrderBy( sqlite3VdbeChangeP5(v, OPFLAG_PERMUTE); sqlite3VdbeAddOp3(v, OP_Jump, addrAltB, addrAeqB, addrAgtB); - /* Release temporary registers - */ - if( regPrev ){ - sqlite3ReleaseTempRange(pParse, regPrev, nOrderBy+1); - } - /* Jump to the this point in order to terminate the query. */ sqlite3VdbeResolveLabel(v, labelEnd); @@ -2962,12 +2960,15 @@ static int flattenSubquery( Select *pNew; ExprList *pOrderBy = p->pOrderBy; Expr *pLimit = p->pLimit; + Expr *pOffset = p->pOffset; Select *pPrior = p->pPrior; p->pOrderBy = 0; p->pSrc = 0; p->pPrior = 0; p->pLimit = 0; + p->pOffset = 0; pNew = sqlite3SelectDup(db, p, 0); + p->pOffset = pOffset; p->pLimit = pLimit; p->pOrderBy = pOrderBy; p->pSrc = pSrc; @@ -3160,34 +3161,43 @@ static int flattenSubquery( #endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */ /* -** Analyze the SELECT statement passed as an argument to see if it -** is a min() or max() query. Return WHERE_ORDERBY_MIN or WHERE_ORDERBY_MAX if -** it is, or 0 otherwise. At present, a query is considered to be -** a min()/max() query if: +** Based on the contents of the AggInfo structure indicated by the first +** argument, this function checks if the following are true: ** -** 1. There is a single object in the FROM clause. +** * the query contains just a single aggregate function, +** * the aggregate function is either min() or max(), and +** * the argument to the aggregate function is a column value. ** -** 2. There is a single expression in the result set, and it is -** either min(x) or max(x), where x is a column reference. +** If all of the above are true, then WHERE_ORDERBY_MIN or WHERE_ORDERBY_MAX +** is returned as appropriate. Also, *ppMinMax is set to point to the +** list of arguments passed to the aggregate before returning. +** +** Or, if the conditions above are not met, *ppMinMax is set to 0 and +** WHERE_ORDERBY_NORMAL is returned. */ -static u8 minMaxQuery(Select *p){ - Expr *pExpr; - ExprList *pEList = p->pEList; - - if( pEList->nExpr!=1 ) return WHERE_ORDERBY_NORMAL; - pExpr = pEList->a[0].pExpr; - if( pExpr->op!=TK_AGG_FUNCTION ) return 0; - if( NEVER(ExprHasProperty(pExpr, EP_xIsSelect)) ) return 0; - pEList = pExpr->x.pList; - if( pEList==0 || pEList->nExpr!=1 ) return 0; - if( pEList->a[0].pExpr->op!=TK_AGG_COLUMN ) return WHERE_ORDERBY_NORMAL; - assert( !ExprHasProperty(pExpr, EP_IntValue) ); - if( sqlite3StrICmp(pExpr->u.zToken,"min")==0 ){ - return WHERE_ORDERBY_MIN; - }else if( sqlite3StrICmp(pExpr->u.zToken,"max")==0 ){ - return WHERE_ORDERBY_MAX; +static u8 minMaxQuery(AggInfo *pAggInfo, ExprList **ppMinMax){ + int eRet = WHERE_ORDERBY_NORMAL; /* Return value */ + + *ppMinMax = 0; + if( pAggInfo->nFunc==1 ){ + Expr *pExpr = pAggInfo->aFunc[0].pExpr; /* Aggregate function */ + ExprList *pEList = pExpr->x.pList; /* Arguments to agg function */ + + assert( pExpr->op==TK_AGG_FUNCTION ); + if( pEList && pEList->nExpr==1 && pEList->a[0].pExpr->op==TK_AGG_COLUMN ){ + const char *zFunc = pExpr->u.zToken; + if( sqlite3StrICmp(zFunc, "min")==0 ){ + eRet = WHERE_ORDERBY_MIN; + *ppMinMax = pEList; + }else if( sqlite3StrICmp(zFunc, "max")==0 ){ + eRet = WHERE_ORDERBY_MAX; + *ppMinMax = pEList; + } + } } - return WHERE_ORDERBY_NORMAL; + + assert( *ppMinMax==0 || (*ppMinMax)->nExpr==1 ); + return eRet; } /* @@ -3250,6 +3260,69 @@ int sqlite3IndexedByLookup(Parse *pParse, struct SrcList_item *pFrom){ } return SQLITE_OK; } +/* +** Detect compound SELECT statements that use an ORDER BY clause with +** an alternative collating sequence. +** +** SELECT ... FROM t1 EXCEPT SELECT ... FROM t2 ORDER BY .. COLLATE ... +** +** These are rewritten as a subquery: +** +** SELECT * FROM (SELECT ... FROM t1 EXCEPT SELECT ... FROM t2) +** ORDER BY ... COLLATE ... +** +** This transformation is necessary because the multiSelectOrderBy() routine +** above that generates the code for a compound SELECT with an ORDER BY clause +** uses a merge algorithm that requires the same collating sequence on the +** result columns as on the ORDER BY clause. See ticket +** http://www.sqlite.org/src/info/6709574d2a +** +** This transformation is only needed for EXCEPT, INTERSECT, and UNION. +** The UNION ALL operator works fine with multiSelectOrderBy() even when +** there are COLLATE terms in the ORDER BY. +*/ +static int convertCompoundSelectToSubquery(Walker *pWalker, Select *p){ + int i; + Select *pNew; + Select *pX; + sqlite3 *db; + struct ExprList_item *a; + SrcList *pNewSrc; + Parse *pParse; + Token dummy; + + if( p->pPrior==0 ) return WRC_Continue; + if( p->pOrderBy==0 ) return WRC_Continue; + for(pX=p; pX && (pX->op==TK_ALL || pX->op==TK_SELECT); pX=pX->pPrior){} + if( pX==0 ) return WRC_Continue; + a = p->pOrderBy->a; + for(i=p->pOrderBy->nExpr-1; i>=0; i--){ + if( a[i].pExpr->flags & EP_Collate ) break; + } + if( i<0 ) return WRC_Continue; + + /* If we reach this point, that means the transformation is required. */ + + pParse = pWalker->pParse; + db = pParse->db; + pNew = sqlite3DbMallocZero(db, sizeof(*pNew) ); + if( pNew==0 ) return WRC_Abort; + memset(&dummy, 0, sizeof(dummy)); + pNewSrc = sqlite3SrcListAppendFromTerm(pParse,0,0,0,&dummy,pNew,0,0); + if( pNewSrc==0 ) return WRC_Abort; + *pNew = *p; + p->pSrc = pNewSrc; + p->pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ALL, 0)); + p->op = TK_SELECT; + p->pWhere = 0; + pNew->pGroupBy = 0; + pNew->pHaving = 0; + pNew->pOrderBy = 0; + p->pPrior = 0; + pNew->pLimit = 0; + pNew->pOffset = 0; + return WRC_Continue; +} /* ** This routine is a Walker callback for "expanding" a SELECT statement. @@ -3282,14 +3355,16 @@ static int selectExpander(Walker *pWalker, Select *p){ ExprList *pEList; struct SrcList_item *pFrom; sqlite3 *db = pParse->db; + Expr *pE, *pRight, *pExpr; + u16 selFlags = p->selFlags; + p->selFlags |= SF_Expanded; if( db->mallocFailed ){ return WRC_Abort; } - if( NEVER(p->pSrc==0) || (p->selFlags & SF_Expanded)!=0 ){ + if( NEVER(p->pSrc==0) || (selFlags & SF_Expanded)!=0 ){ return WRC_Prune; } - p->selFlags |= SF_Expanded; pTabList = p->pSrc; pEList = p->pEList; @@ -3332,6 +3407,12 @@ static int selectExpander(Walker *pWalker, Select *p){ assert( pFrom->pTab==0 ); pFrom->pTab = pTab = sqlite3LocateTableItem(pParse, 0, pFrom); if( pTab==0 ) return WRC_Abort; + if( pTab->nRef==0xffff ){ + sqlite3ErrorMsg(pParse, "too many references to \"%s\": max 65535", + pTab->zName); + pFrom->pTab = 0; + return WRC_Abort; + } pTab->nRef++; #if !defined(SQLITE_OMIT_VIEW) || !defined (SQLITE_OMIT_VIRTUALTABLE) if( pTab->pSelect || IsVirtual(pTab) ){ @@ -3367,7 +3448,7 @@ static int selectExpander(Walker *pWalker, Select *p){ ** that need expanding. */ for(k=0; k<pEList->nExpr; k++){ - Expr *pE = pEList->a[k].pExpr; + pE = pEList->a[k].pExpr; if( pE->op==TK_ALL ) break; assert( pE->op!=TK_DOT || pE->pRight!=0 ); assert( pE->op!=TK_DOT || (pE->pLeft!=0 && pE->pLeft->op==TK_ID) ); @@ -3385,10 +3466,18 @@ static int selectExpander(Walker *pWalker, Select *p){ int longNames = (flags & SQLITE_FullColNames)!=0 && (flags & SQLITE_ShortColNames)==0; + /* When processing FROM-clause subqueries, it is always the case + ** that full_column_names=OFF and short_column_names=ON. The + ** sqlite3ResultSetOfSelect() routine makes it so. */ + assert( (p->selFlags & SF_NestedFrom)==0 + || ((flags & SQLITE_FullColNames)==0 && + (flags & SQLITE_ShortColNames)!=0) ); + for(k=0; k<pEList->nExpr; k++){ - Expr *pE = a[k].pExpr; - assert( pE->op!=TK_DOT || pE->pRight!=0 ); - if( pE->op!=TK_ALL && (pE->op!=TK_DOT || pE->pRight->op!=TK_ALL) ){ + pE = a[k].pExpr; + pRight = pE->pRight; + assert( pE->op!=TK_DOT || pRight!=0 ); + if( pE->op!=TK_ALL && (pE->op!=TK_DOT || pRight->op!=TK_ALL) ){ /* This particular expression does not need to be expanded. */ pNew = sqlite3ExprListAppend(pParse, pNew, a[k].pExpr); @@ -3403,32 +3492,43 @@ static int selectExpander(Walker *pWalker, Select *p){ /* This expression is a "*" or a "TABLE.*" and needs to be ** expanded. */ int tableSeen = 0; /* Set to 1 when TABLE matches */ - char *zTName; /* text of name of TABLE */ + char *zTName = 0; /* text of name of TABLE */ if( pE->op==TK_DOT ){ assert( pE->pLeft!=0 ); assert( !ExprHasProperty(pE->pLeft, EP_IntValue) ); zTName = pE->pLeft->u.zToken; - }else{ - zTName = 0; } for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){ Table *pTab = pFrom->pTab; + Select *pSub = pFrom->pSelect; char *zTabName = pFrom->zAlias; + const char *zSchemaName = 0; + int iDb; if( zTabName==0 ){ zTabName = pTab->zName; } if( db->mallocFailed ) break; - if( zTName && sqlite3StrICmp(zTName, zTabName)!=0 ){ - continue; + if( pSub==0 || (pSub->selFlags & SF_NestedFrom)==0 ){ + pSub = 0; + if( zTName && sqlite3StrICmp(zTName, zTabName)!=0 ){ + continue; + } + iDb = sqlite3SchemaToIndex(db, pTab->pSchema); + zSchemaName = iDb>=0 ? db->aDb[iDb].zName : "*"; } - tableSeen = 1; for(j=0; j<pTab->nCol; j++){ - Expr *pExpr, *pRight; char *zName = pTab->aCol[j].zName; char *zColname; /* The computed column name */ char *zToFree; /* Malloced string that needs to be freed */ Token sColname; /* Computed column name as a token */ + assert( zName ); + if( zTName && pSub + && sqlite3MatchSpanName(pSub->pEList->a[j].zSpan, 0, zTName, 0)==0 + ){ + continue; + } + /* If a column is marked as 'hidden' (currently only possible ** for virtual tables), do not include it in the expanded ** result-set list. @@ -3437,6 +3537,7 @@ static int selectExpander(Walker *pWalker, Select *p){ assert(IsVirtual(pTab)); continue; } + tableSeen = 1; if( i>0 && zTName==0 ){ if( (pFrom->jointype & JT_NATURAL)!=0 @@ -3459,6 +3560,10 @@ static int selectExpander(Walker *pWalker, Select *p){ Expr *pLeft; pLeft = sqlite3Expr(db, TK_ID, zTabName); pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight, 0); + if( zSchemaName ){ + pLeft = sqlite3Expr(db, TK_ID, zSchemaName); + pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pExpr, 0); + } if( longNames ){ zColname = sqlite3MPrintf(db, "%s.%s", zTabName, zName); zToFree = zColname; @@ -3470,6 +3575,18 @@ static int selectExpander(Walker *pWalker, Select *p){ sColname.z = zColname; sColname.n = sqlite3Strlen30(zColname); sqlite3ExprListSetName(pParse, pNew, &sColname, 0); + if( pNew && (p->selFlags & SF_NestedFrom)!=0 ){ + struct ExprList_item *pX = &pNew->a[pNew->nExpr-1]; + if( pSub ){ + pX->zSpan = sqlite3DbStrDup(db, pSub->pEList->a[j].zSpan); + testcase( pX->zSpan==0 ); + }else{ + pX->zSpan = sqlite3MPrintf(db, "%s.%s.%s", + zSchemaName, zTabName, zColname); + testcase( pX->zSpan==0 ); + } + pX->bSpanIsTab = 1; + } sqlite3DbFree(db, zToFree); } } @@ -3522,10 +3639,13 @@ static int exprWalkNoop(Walker *NotUsed, Expr *NotUsed2){ */ static void sqlite3SelectExpand(Parse *pParse, Select *pSelect){ Walker w; - w.xSelectCallback = selectExpander; + memset(&w, 0, sizeof(w)); + w.xSelectCallback = convertCompoundSelectToSubquery; w.xExprCallback = exprWalkNoop; w.pParse = pParse; sqlite3WalkSelect(&w, pSelect); + w.xSelectCallback = selectExpander; + sqlite3WalkSelect(&w, pSelect); } @@ -3580,9 +3700,11 @@ static int selectAddSubqueryTypeInfo(Walker *pWalker, Select *p){ static void sqlite3SelectAddTypeInfo(Parse *pParse, Select *pSelect){ #ifndef SQLITE_OMIT_SUBQUERY Walker w; + memset(&w, 0, sizeof(w)); w.xSelectCallback = selectAddSubqueryTypeInfo; w.xExprCallback = exprWalkNoop; w.pParse = pParse; + w.bSelectDepthFirst = 1; sqlite3WalkSelect(&w, pSelect); #endif } @@ -3608,6 +3730,7 @@ void sqlite3SelectPrep( sqlite3 *db; if( NEVER(p==0) ) return; db = pParse->db; + if( db->mallocFailed ) return; if( p->selFlags & SF_HasTypeInfo ) return; sqlite3SelectExpand(pParse, p); if( pParse->nErr || db->mallocFailed ) return; @@ -3992,7 +4115,7 @@ int sqlite3Select( pItem->addrFillSub = topAddr+1; VdbeNoopComment((v, "materialize %s", pItem->pTab->zName)); if( pItem->isCorrelated==0 ){ - /* If the subquery is no correlated and if we are not inside of + /* If the subquery is not correlated and if we are not inside of ** a trigger, then we only need to compute the value of the subquery ** once. */ onceAddr = sqlite3CodeOnce(pParse); @@ -4515,7 +4638,7 @@ int sqlite3Select( ** value of x, the only row required). ** ** A special flag must be passed to sqlite3WhereBegin() to slightly - ** modify behaviour as follows: + ** modify behavior as follows: ** ** + If the query is a "SELECT min(x)", then the loop coded by ** where.c should not iterate over any values with a NULL value @@ -4527,11 +4650,17 @@ int sqlite3Select( ** Refer to code and comments in where.c for details. */ ExprList *pMinMax = 0; - u8 flag = minMaxQuery(p); + u8 flag = WHERE_ORDERBY_NORMAL; + + assert( p->pGroupBy==0 ); + assert( flag==0 ); + if( p->pHaving==0 ){ + flag = minMaxQuery(&sAggInfo, &pMinMax); + } + assert( flag==0 || (pMinMax!=0 && pMinMax->nExpr==1) ); + if( flag ){ - assert( !ExprHasProperty(p->pEList->a[0].pExpr, EP_xIsSelect) ); - assert( p->pEList->a[0].pExpr->x.pList->nExpr==1 ); - pMinMax = sqlite3ExprListDup(db, p->pEList->a[0].pExpr->x.pList,0); + pMinMax = sqlite3ExprListDup(db, pMinMax, 0); pDel = pMinMax; if( pMinMax && !db->mallocFailed ){ pMinMax->a[0].sortOrder = flag!=WHERE_ORDERBY_MIN ?1:0; @@ -4687,7 +4816,10 @@ void sqlite3ExplainSelect(Vdbe *pVdbe, Select *p){ sqlite3ExplainPrintf(pVdbe, "(null-select)"); return; } - while( p->pPrior ) p = p->pPrior; + while( p->pPrior ){ + p->pPrior->pNext = p; + p = p->pPrior; + } sqlite3ExplainPush(pVdbe); while( p ){ explainOneSelect(pVdbe, p); |