| /* |
| ** 2001 September 15 |
| ** |
| ** The author disclaims copyright to this source code. In place of |
| ** a legal notice, here is a blessing: |
| ** |
| ** May you do good and not evil. |
| ** May you find forgiveness for yourself and forgive others. |
| ** May you share freely, never taking more than you give. |
| ** |
| ************************************************************************* |
| ** This file contains C code routines that are called by the parser |
| ** to handle SELECT statements in SQLite. |
| */ |
| #include "sqliteInt.h" |
| |
| |
| /* |
| ** Delete all the content of a Select structure but do not deallocate |
| ** the select structure itself. |
| */ |
| static void clearSelect(sqlite3 *db, Select *p){ |
| sqlite3ExprListDelete(db, p->pEList); |
| sqlite3SrcListDelete(db, p->pSrc); |
| sqlite3ExprDelete(db, p->pWhere); |
| sqlite3ExprListDelete(db, p->pGroupBy); |
| sqlite3ExprDelete(db, p->pHaving); |
| sqlite3ExprListDelete(db, p->pOrderBy); |
| sqlite3SelectDelete(db, p->pPrior); |
| sqlite3ExprDelete(db, p->pLimit); |
| sqlite3ExprDelete(db, p->pOffset); |
| } |
| |
| /* |
| ** Initialize a SelectDest structure. |
| */ |
| void sqlite3SelectDestInit(SelectDest *pDest, int eDest, int iParm){ |
| pDest->eDest = (u8)eDest; |
| pDest->iParm = iParm; |
| pDest->affinity = 0; |
| pDest->iMem = 0; |
| pDest->nMem = 0; |
| } |
| |
| |
| /* |
| ** Allocate a new Select structure and return a pointer to that |
| ** structure. |
| */ |
| Select *sqlite3SelectNew( |
| Parse *pParse, /* Parsing context */ |
| ExprList *pEList, /* which columns to include in the result */ |
| SrcList *pSrc, /* the FROM clause -- which tables to scan */ |
| Expr *pWhere, /* the WHERE clause */ |
| 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 */ |
| Expr *pLimit, /* LIMIT value. NULL means not used */ |
| Expr *pOffset /* OFFSET value. NULL means no offset */ |
| ){ |
| Select *pNew; |
| Select standin; |
| sqlite3 *db = pParse->db; |
| pNew = sqlite3DbMallocZero(db, sizeof(*pNew) ); |
| assert( db->mallocFailed || !pOffset || pLimit ); /* OFFSET implies LIMIT */ |
| if( pNew==0 ){ |
| pNew = &standin; |
| memset(pNew, 0, sizeof(*pNew)); |
| } |
| if( pEList==0 ){ |
| pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db,TK_ALL,0)); |
| } |
| pNew->pEList = pEList; |
| pNew->pSrc = pSrc; |
| pNew->pWhere = pWhere; |
| pNew->pGroupBy = pGroupBy; |
| pNew->pHaving = pHaving; |
| pNew->pOrderBy = pOrderBy; |
| pNew->selFlags = isDistinct ? SF_Distinct : 0; |
| pNew->op = TK_SELECT; |
| pNew->pLimit = pLimit; |
| pNew->pOffset = pOffset; |
| assert( pOffset==0 || pLimit!=0 ); |
| pNew->addrOpenEphm[0] = -1; |
| pNew->addrOpenEphm[1] = -1; |
| pNew->addrOpenEphm[2] = -1; |
| if( db->mallocFailed ) { |
| clearSelect(db, pNew); |
| if( pNew!=&standin ) sqlite3DbFree(db, pNew); |
| pNew = 0; |
| } |
| return pNew; |
| } |
| |
| /* |
| ** Delete the given Select structure and all of its substructures. |
| */ |
| void sqlite3SelectDelete(sqlite3 *db, Select *p){ |
| if( p ){ |
| clearSelect(db, p); |
| sqlite3DbFree(db, p); |
| } |
| } |
| |
| /* |
| ** Given 1 to 3 identifiers preceeding the JOIN keyword, determine the |
| ** type of join. Return an integer constant that expresses that type |
| ** in terms of the following bit values: |
| ** |
| ** JT_INNER |
| ** JT_CROSS |
| ** JT_OUTER |
| ** JT_NATURAL |
| ** JT_LEFT |
| ** JT_RIGHT |
| ** |
| ** A full outer join is the combination of JT_LEFT and JT_RIGHT. |
| ** |
| ** If an illegal or unsupported join type is seen, then still return |
| ** a join type, but put an error in the pParse structure. |
| */ |
| int sqlite3JoinType(Parse *pParse, Token *pA, Token *pB, Token *pC){ |
| int jointype = 0; |
| Token *apAll[3]; |
| Token *p; |
| /* 0123456789 123456789 123456789 123 */ |
| static const char zKeyText[] = "naturaleftouterightfullinnercross"; |
| static const struct { |
| u8 i; /* Beginning of keyword text in zKeyText[] */ |
| u8 nChar; /* Length of the keyword in characters */ |
| u8 code; /* Join type mask */ |
| } aKeyword[] = { |
| /* natural */ { 0, 7, JT_NATURAL }, |
| /* left */ { 6, 4, JT_LEFT|JT_OUTER }, |
| /* outer */ { 10, 5, JT_OUTER }, |
| /* right */ { 14, 5, JT_RIGHT|JT_OUTER }, |
| /* full */ { 19, 4, JT_LEFT|JT_RIGHT|JT_OUTER }, |
| /* inner */ { 23, 5, JT_INNER }, |
| /* cross */ { 28, 5, JT_INNER|JT_CROSS }, |
| }; |
| int i, j; |
| apAll[0] = pA; |
| apAll[1] = pB; |
| apAll[2] = pC; |
| for(i=0; i<3 && apAll[i]; i++){ |
| p = apAll[i]; |
| for(j=0; j<ArraySize(aKeyword); j++){ |
| if( p->n==aKeyword[j].nChar |
| && sqlite3StrNICmp((char*)p->z, &zKeyText[aKeyword[j].i], p->n)==0 ){ |
| jointype |= aKeyword[j].code; |
| break; |
| } |
| } |
| testcase( j==0 || j==1 || j==2 || j==3 || j==4 || j==5 || j==6 ); |
| if( j>=ArraySize(aKeyword) ){ |
| jointype |= JT_ERROR; |
| break; |
| } |
| } |
| if( |
| (jointype & (JT_INNER|JT_OUTER))==(JT_INNER|JT_OUTER) || |
| (jointype & JT_ERROR)!=0 |
| ){ |
| const char *zSp = " "; |
| assert( pB!=0 ); |
| if( pC==0 ){ zSp++; } |
| sqlite3ErrorMsg(pParse, "unknown or unsupported join type: " |
| "%T %T%s%T", pA, pB, zSp, pC); |
| jointype = JT_INNER; |
| }else if( (jointype & JT_OUTER)!=0 |
| && (jointype & (JT_LEFT|JT_RIGHT))!=JT_LEFT ){ |
| sqlite3ErrorMsg(pParse, |
| "RIGHT and FULL OUTER JOINs are not currently supported"); |
| jointype = JT_INNER; |
| } |
| return jointype; |
| } |
| |
| /* |
| ** Return the index of a column in a table. Return -1 if the column |
| ** is not contained in the table. |
| */ |
| static int columnIndex(Table *pTab, const char *zCol){ |
| int i; |
| for(i=0; i<pTab->nCol; i++){ |
| if( sqlite3StrICmp(pTab->aCol[i].zName, zCol)==0 ) return i; |
| } |
| return -1; |
| } |
| |
| /* |
| ** Search the first N tables in pSrc, from left to right, looking for a |
| ** table that has a column named zCol. |
| ** |
| ** When found, set *piTab and *piCol to the table index and column index |
| ** of the matching column and return TRUE. |
| ** |
| ** If not found, return FALSE. |
| */ |
| static int tableAndColumnIndex( |
| SrcList *pSrc, /* Array of tables to search */ |
| int N, /* Number of tables in pSrc->a[] to search */ |
| const char *zCol, /* Name of the column we are looking for */ |
| int *piTab, /* Write index of pSrc->a[] here */ |
| int *piCol /* Write index of pSrc->a[*piTab].pTab->aCol[] here */ |
| ){ |
| int i; /* For looping over tables in pSrc */ |
| int iCol; /* Index of column matching zCol */ |
| |
| assert( (piTab==0)==(piCol==0) ); /* Both or neither are NULL */ |
| for(i=0; i<N; i++){ |
| iCol = columnIndex(pSrc->a[i].pTab, zCol); |
| if( iCol>=0 ){ |
| if( piTab ){ |
| *piTab = i; |
| *piCol = iCol; |
| } |
| return 1; |
| } |
| } |
| return 0; |
| } |
| |
| /* |
| ** This function is used to add terms implied by JOIN syntax to the |
| ** WHERE clause expression of a SELECT statement. The new term, which |
| ** is ANDed with the existing WHERE clause, is of the form: |
| ** |
| ** (tab1.col1 = tab2.col2) |
| ** |
| ** where tab1 is the iSrc'th table in SrcList pSrc and tab2 is the |
| ** (iSrc+1)'th. Column col1 is column iColLeft of tab1, and col2 is |
| ** column iColRight of tab2. |
| */ |
| static void addWhereTerm( |
| Parse *pParse, /* Parsing context */ |
| SrcList *pSrc, /* List of tables in FROM clause */ |
| int iLeft, /* Index of first table to join in pSrc */ |
| int iColLeft, /* Index of column in first table */ |
| int iRight, /* Index of second table in pSrc */ |
| int iColRight, /* Index of column in second table */ |
| int isOuterJoin, /* True if this is an OUTER join */ |
| Expr **ppWhere /* IN/OUT: The WHERE clause to add to */ |
| ){ |
| sqlite3 *db = pParse->db; |
| Expr *pE1; |
| Expr *pE2; |
| Expr *pEq; |
| |
| assert( iLeft<iRight ); |
| assert( pSrc->nSrc>iRight ); |
| assert( pSrc->a[iLeft].pTab ); |
| assert( pSrc->a[iRight].pTab ); |
| |
| pE1 = sqlite3CreateColumnExpr(db, pSrc, iLeft, iColLeft); |
| pE2 = sqlite3CreateColumnExpr(db, pSrc, iRight, iColRight); |
| |
| pEq = sqlite3PExpr(pParse, TK_EQ, pE1, pE2, 0); |
| if( pEq && isOuterJoin ){ |
| ExprSetProperty(pEq, EP_FromJoin); |
| assert( !ExprHasAnyProperty(pEq, EP_TokenOnly|EP_Reduced) ); |
| ExprSetIrreducible(pEq); |
| pEq->iRightJoinTable = (i16)pE2->iTable; |
| } |
| *ppWhere = sqlite3ExprAnd(db, *ppWhere, pEq); |
| } |
| |
| /* |
| ** Set the EP_FromJoin property on all terms of the given expression. |
| ** And set the Expr.iRightJoinTable to iTable for every term in the |
| ** expression. |
| ** |
| ** The EP_FromJoin property is used on terms of an expression to tell |
| ** the LEFT OUTER JOIN processing logic that this term is part of the |
| ** join restriction specified in the ON or USING clause and not a part |
| ** of the more general WHERE clause. These terms are moved over to the |
| ** WHERE clause during join processing but we need to remember that they |
| ** originated in the ON or USING clause. |
| ** |
| ** The Expr.iRightJoinTable tells the WHERE clause processing that the |
| ** expression depends on table iRightJoinTable even if that table is not |
| ** explicitly mentioned in the expression. That information is needed |
| ** for cases like this: |
| ** |
| ** SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.b AND t1.x=5 |
| ** |
| ** The where clause needs to defer the handling of the t1.x=5 |
| ** term until after the t2 loop of the join. In that way, a |
| ** NULL t2 row will be inserted whenever t1.x!=5. If we do not |
| ** defer the handling of t1.x=5, it will be processed immediately |
| ** after the t1 loop and rows with t1.x!=5 will never appear in |
| ** the output, which is incorrect. |
| */ |
| static void setJoinExpr(Expr *p, int iTable){ |
| while( p ){ |
| ExprSetProperty(p, EP_FromJoin); |
| assert( !ExprHasAnyProperty(p, EP_TokenOnly|EP_Reduced) ); |
| ExprSetIrreducible(p); |
| p->iRightJoinTable = (i16)iTable; |
| setJoinExpr(p->pLeft, iTable); |
| p = p->pRight; |
| } |
| } |
| |
| /* |
| ** This routine processes the join information for a SELECT statement. |
| ** ON and USING clauses are converted into extra terms of the WHERE clause. |
| ** NATURAL joins also create extra WHERE clause terms. |
| ** |
| ** The terms of a FROM clause are contained in the Select.pSrc structure. |
| ** The left most table is the first entry in Select.pSrc. The right-most |
| ** table is the last entry. The join operator is held in the entry to |
| ** the left. Thus entry 0 contains the join operator for the join between |
| ** entries 0 and 1. Any ON or USING clauses associated with the join are |
| ** also attached to the left entry. |
| ** |
| ** This routine returns the number of errors encountered. |
| */ |
| static int sqliteProcessJoin(Parse *pParse, Select *p){ |
| SrcList *pSrc; /* All tables in the FROM clause */ |
| int i, j; /* Loop counters */ |
| struct SrcList_item *pLeft; /* Left table being joined */ |
| struct SrcList_item *pRight; /* Right table being joined */ |
| |
| pSrc = p->pSrc; |
| pLeft = &pSrc->a[0]; |
| pRight = &pLeft[1]; |
| for(i=0; i<pSrc->nSrc-1; i++, pRight++, pLeft++){ |
| Table *pLeftTab = pLeft->pTab; |
| Table *pRightTab = pRight->pTab; |
| int isOuter; |
| |
| if( NEVER(pLeftTab==0 || pRightTab==0) ) continue; |
| isOuter = (pRight->jointype & JT_OUTER)!=0; |
| |
| /* When the NATURAL keyword is present, add WHERE clause terms for |
| ** every column that the two tables have in common. |
| */ |
| if( pRight->jointype & JT_NATURAL ){ |
| if( pRight->pOn || pRight->pUsing ){ |
| sqlite3ErrorMsg(pParse, "a NATURAL join may not have " |
| "an ON or USING clause", 0); |
| return 1; |
| } |
| for(j=0; j<pRightTab->nCol; j++){ |
| char *zName; /* Name of column in the right table */ |
| int iLeft; /* Matching left table */ |
| int iLeftCol; /* Matching column in the left table */ |
| |
| zName = pRightTab->aCol[j].zName; |
| if( tableAndColumnIndex(pSrc, i+1, zName, &iLeft, &iLeftCol) ){ |
| addWhereTerm(pParse, pSrc, iLeft, iLeftCol, i+1, j, |
| isOuter, &p->pWhere); |
| } |
| } |
| } |
| |
| /* Disallow both ON and USING clauses in the same join |
| */ |
| if( pRight->pOn && pRight->pUsing ){ |
| sqlite3ErrorMsg(pParse, "cannot have both ON and USING " |
| "clauses in the same join"); |
| return 1; |
| } |
| |
| /* Add the ON clause to the end of the WHERE clause, connected by |
| ** an AND operator. |
| */ |
| if( pRight->pOn ){ |
| if( isOuter ) setJoinExpr(pRight->pOn, pRight->iCursor); |
| p->pWhere = sqlite3ExprAnd(pParse->db, p->pWhere, pRight->pOn); |
| pRight->pOn = 0; |
| } |
| |
| /* Create extra terms on the WHERE clause for each column named |
| ** in the USING clause. Example: If the two tables to be joined are |
| ** A and B and the USING clause names X, Y, and Z, then add this |
| ** to the WHERE clause: A.X=B.X AND A.Y=B.Y AND A.Z=B.Z |
| ** Report an error if any column mentioned in the USING clause is |
| ** not contained in both tables to be joined. |
| */ |
| if( pRight->pUsing ){ |
| IdList *pList = pRight->pUsing; |
| for(j=0; j<pList->nId; j++){ |
| char *zName; /* Name of the term in the USING clause */ |
| int iLeft; /* Table on the left with matching column name */ |
| int iLeftCol; /* Column number of matching column on the left */ |
| int iRightCol; /* Column number of matching column on the right */ |
| |
| zName = pList->a[j].zName; |
| iRightCol = columnIndex(pRightTab, zName); |
| if( iRightCol<0 |
| || !tableAndColumnIndex(pSrc, i+1, zName, &iLeft, &iLeftCol) |
| ){ |
| sqlite3ErrorMsg(pParse, "cannot join using column %s - column " |
| "not present in both tables", zName); |
| return 1; |
| } |
| addWhereTerm(pParse, pSrc, iLeft, iLeftCol, i+1, iRightCol, |
| isOuter, &p->pWhere); |
| } |
| } |
| } |
| return 0; |
| } |
| |
| /* |
| ** Insert code into "v" that will push the record on the top of the |
| ** stack into the sorter. |
| */ |
| static void pushOntoSorter( |
| Parse *pParse, /* Parser context */ |
| ExprList *pOrderBy, /* The ORDER BY clause */ |
| Select *pSelect, /* The whole SELECT statement */ |
| int regData /* Register holding data to be sorted */ |
| ){ |
| Vdbe *v = pParse->pVdbe; |
| int nExpr = pOrderBy->nExpr; |
| int regBase = sqlite3GetTempRange(pParse, nExpr+2); |
| int regRecord = sqlite3GetTempReg(pParse); |
| sqlite3ExprCacheClear(pParse); |
| sqlite3ExprCodeExprList(pParse, pOrderBy, regBase, 0); |
| sqlite3VdbeAddOp2(v, OP_Sequence, pOrderBy->iECursor, regBase+nExpr); |
| sqlite3ExprCodeMove(pParse, regData, regBase+nExpr+1, 1); |
| sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nExpr + 2, regRecord); |
| sqlite3VdbeAddOp2(v, OP_IdxInsert, pOrderBy->iECursor, regRecord); |
| sqlite3ReleaseTempReg(pParse, regRecord); |
| sqlite3ReleaseTempRange(pParse, regBase, nExpr+2); |
| if( pSelect->iLimit ){ |
| int addr1, addr2; |
| int iLimit; |
| if( pSelect->iOffset ){ |
| iLimit = pSelect->iOffset+1; |
| }else{ |
| iLimit = pSelect->iLimit; |
| } |
| addr1 = sqlite3VdbeAddOp1(v, OP_IfZero, iLimit); |
| sqlite3VdbeAddOp2(v, OP_AddImm, iLimit, -1); |
| addr2 = sqlite3VdbeAddOp0(v, OP_Goto); |
| sqlite3VdbeJumpHere(v, addr1); |
| sqlite3VdbeAddOp1(v, OP_Last, pOrderBy->iECursor); |
| sqlite3VdbeAddOp1(v, OP_Delete, pOrderBy->iECursor); |
| sqlite3VdbeJumpHere(v, addr2); |
| } |
| } |
| |
| /* |
| ** Add code to implement the OFFSET |
| */ |
| static void codeOffset( |
| Vdbe *v, /* Generate code into this VM */ |
| Select *p, /* The SELECT statement being coded */ |
| int iContinue /* Jump here to skip the current record */ |
| ){ |
| if( p->iOffset && iContinue!=0 ){ |
| int addr; |
| sqlite3VdbeAddOp2(v, OP_AddImm, p->iOffset, -1); |
| addr = sqlite3VdbeAddOp1(v, OP_IfNeg, p->iOffset); |
| sqlite3VdbeAddOp2(v, OP_Goto, 0, iContinue); |
| VdbeComment((v, "skip OFFSET records")); |
| sqlite3VdbeJumpHere(v, addr); |
| } |
| } |
| |
| /* |
| ** Add code that will check to make sure the N registers starting at iMem |
| ** form a distinct entry. iTab is a sorting index that holds previously |
| ** seen combinations of the N values. A new entry is made in iTab |
| ** if the current N values are new. |
| ** |
| ** A jump to addrRepeat is made and the N+1 values are popped from the |
| ** stack if the top N elements are not distinct. |
| */ |
| static void codeDistinct( |
| Parse *pParse, /* Parsing and code generating context */ |
| int iTab, /* A sorting index used to test for distinctness */ |
| int addrRepeat, /* Jump to here if not distinct */ |
| int N, /* Number of elements */ |
| int iMem /* First element */ |
| ){ |
| Vdbe *v; |
| int r1; |
| |
| v = pParse->pVdbe; |
| r1 = sqlite3GetTempReg(pParse); |
| sqlite3VdbeAddOp4Int(v, OP_Found, iTab, addrRepeat, iMem, N); |
| sqlite3VdbeAddOp3(v, OP_MakeRecord, iMem, N, r1); |
| sqlite3VdbeAddOp2(v, OP_IdxInsert, iTab, r1); |
| sqlite3ReleaseTempReg(pParse, r1); |
| } |
| |
| #ifndef SQLITE_OMIT_SUBQUERY |
| /* |
| ** Generate an error message when a SELECT is used within a subexpression |
| ** (example: "a IN (SELECT * FROM table)") but it has more than 1 result |
| ** column. We do this in a subroutine because the error used to occur |
| ** in multiple places. (The error only occurs in one place now, but we |
| ** retain the subroutine to minimize code disruption.) |
| */ |
| static int checkForMultiColumnSelectError( |
| Parse *pParse, /* Parse context. */ |
| SelectDest *pDest, /* Destination of SELECT results */ |
| int nExpr /* Number of result columns returned by SELECT */ |
| ){ |
| int eDest = pDest->eDest; |
| if( nExpr>1 && (eDest==SRT_Mem || eDest==SRT_Set) ){ |
| sqlite3ErrorMsg(pParse, "only a single result allowed for " |
| "a SELECT that is part of an expression"); |
| return 1; |
| }else{ |
| return 0; |
| } |
| } |
| #endif |
| |
| /* |
| ** This routine generates the code for the inside of the inner loop |
| ** of a SELECT. |
| ** |
| ** If srcTab and nColumn are both zero, then the pEList expressions |
| ** are evaluated in order to get the data for this row. If nColumn>0 |
| ** then data is pulled from srcTab and pEList is used only to get the |
| ** datatypes for each column. |
| */ |
| static void selectInnerLoop( |
| Parse *pParse, /* The parser context */ |
| Select *p, /* The complete select statement being coded */ |
| ExprList *pEList, /* List of values being extracted */ |
| int srcTab, /* Pull data from this table */ |
| int nColumn, /* Number of columns in the source table */ |
| ExprList *pOrderBy, /* If not NULL, sort results using this key */ |
| int distinct, /* If >=0, make sure results are distinct */ |
| SelectDest *pDest, /* How to dispose of the results */ |
| int iContinue, /* Jump here to continue with next row */ |
| int iBreak /* Jump here to break out of the inner loop */ |
| ){ |
| Vdbe *v = pParse->pVdbe; |
| int i; |
| int hasDistinct; /* True if the DISTINCT keyword is present */ |
| int regResult; /* Start of memory holding result set */ |
| int eDest = pDest->eDest; /* How to dispose of results */ |
| int iParm = pDest->iParm; /* First argument to disposal method */ |
| int nResultCol; /* Number of result columns */ |
| |
| assert( v ); |
| if( NEVER(v==0) ) return; |
| assert( pEList!=0 ); |
| hasDistinct = distinct>=0; |
| if( pOrderBy==0 && !hasDistinct ){ |
| codeOffset(v, p, iContinue); |
| } |
| |
| /* Pull the requested columns. |
| */ |
| if( nColumn>0 ){ |
| nResultCol = nColumn; |
| }else{ |
| nResultCol = pEList->nExpr; |
| } |
| if( pDest->iMem==0 ){ |
| pDest->iMem = pParse->nMem+1; |
| pDest->nMem = nResultCol; |
| pParse->nMem += nResultCol; |
| }else{ |
| assert( pDest->nMem==nResultCol ); |
| } |
| regResult = pDest->iMem; |
| if( nColumn>0 ){ |
| for(i=0; i<nColumn; i++){ |
| sqlite3VdbeAddOp3(v, OP_Column, srcTab, i, regResult+i); |
| } |
| }else if( eDest!=SRT_Exists ){ |
| /* If the destination is an EXISTS(...) expression, the actual |
| ** values returned by the SELECT are not required. |
| */ |
| sqlite3ExprCacheClear(pParse); |
| sqlite3ExprCodeExprList(pParse, pEList, regResult, eDest==SRT_Output); |
| } |
| nColumn = nResultCol; |
| |
| /* If the DISTINCT keyword was present on the SELECT statement |
| ** and this row has been seen before, then do not make this row |
| ** part of the result. |
| */ |
| if( hasDistinct ){ |
| assert( pEList!=0 ); |
| assert( pEList->nExpr==nColumn ); |
| codeDistinct(pParse, distinct, iContinue, nColumn, regResult); |
| if( pOrderBy==0 ){ |
| codeOffset(v, p, iContinue); |
| } |
| } |
| |
| switch( eDest ){ |
| /* In this mode, write each query result to the key of the temporary |
| ** table iParm. |
| */ |
| #ifndef SQLITE_OMIT_COMPOUND_SELECT |
| case SRT_Union: { |
| int r1; |
| r1 = sqlite3GetTempReg(pParse); |
| sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nColumn, r1); |
| sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1); |
| sqlite3ReleaseTempReg(pParse, r1); |
| break; |
| } |
| |
| /* Construct a record from the query result, but instead of |
| ** saving that record, use it as a key to delete elements from |
| ** the temporary table iParm. |
| */ |
| case SRT_Except: { |
| sqlite3VdbeAddOp3(v, OP_IdxDelete, iParm, regResult, nColumn); |
| break; |
| } |
| #endif |
| |
| /* Store the result as data using a unique key. |
| */ |
| case SRT_Table: |
| case SRT_EphemTab: { |
| int r1 = sqlite3GetTempReg(pParse); |
| testcase( eDest==SRT_Table ); |
| testcase( eDest==SRT_EphemTab ); |
| sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nColumn, r1); |
| if( pOrderBy ){ |
| pushOntoSorter(pParse, pOrderBy, p, r1); |
| }else{ |
| int r2 = sqlite3GetTempReg(pParse); |
| sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, r2); |
| sqlite3VdbeAddOp3(v, OP_Insert, iParm, r1, r2); |
| sqlite3VdbeChangeP5(v, OPFLAG_APPEND); |
| sqlite3ReleaseTempReg(pParse, r2); |
| } |
| sqlite3ReleaseTempReg(pParse, r1); |
| break; |
| } |
| |
| #ifndef SQLITE_OMIT_SUBQUERY |
| /* If we are creating a set for an "expr IN (SELECT ...)" construct, |
| ** then there should be a single item on the stack. Write this |
| ** item into the set table with bogus data. |
| */ |
| case SRT_Set: { |
| assert( nColumn==1 ); |
| p->affinity = sqlite3CompareAffinity(pEList->a[0].pExpr, pDest->affinity); |
| if( pOrderBy ){ |
| /* At first glance you would think we could optimize out the |
| ** ORDER BY in this case since the order of entries in the set |
| ** does not matter. But there might be a LIMIT clause, in which |
| ** case the order does matter */ |
| pushOntoSorter(pParse, pOrderBy, p, regResult); |
| }else{ |
| int r1 = sqlite3GetTempReg(pParse); |
| sqlite3VdbeAddOp4(v, OP_MakeRecord, regResult, 1, r1, &p->affinity, 1); |
| sqlite3ExprCacheAffinityChange(pParse, regResult, 1); |
| sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1); |
| sqlite3ReleaseTempReg(pParse, r1); |
| } |
| break; |
| } |
| |
| /* If any row exist in the result set, record that fact and abort. |
| */ |
| case SRT_Exists: { |
| sqlite3VdbeAddOp2(v, OP_Integer, 1, iParm); |
| /* The LIMIT clause will terminate the loop for us */ |
| break; |
| } |
| |
| /* If this is a scalar select that is part of an expression, then |
| ** store the results in the appropriate memory cell and break out |
| ** of the scan loop. |
| */ |
| case SRT_Mem: { |
| assert( nColumn==1 ); |
| if( pOrderBy ){ |
| pushOntoSorter(pParse, pOrderBy, p, regResult); |
| }else{ |
| sqlite3ExprCodeMove(pParse, regResult, iParm, 1); |
| /* The LIMIT clause will jump out of the loop for us */ |
| } |
| break; |
| } |
| #endif /* #ifndef SQLITE_OMIT_SUBQUERY */ |
| |
| /* Send the data to the callback function or to a subroutine. In the |
| ** case of a subroutine, the subroutine itself is responsible for |
| ** popping the data from the stack. |
| */ |
| case SRT_Coroutine: |
| case SRT_Output: { |
| testcase( eDest==SRT_Coroutine ); |
| testcase( eDest==SRT_Output ); |
| if( pOrderBy ){ |
| int r1 = sqlite3GetTempReg(pParse); |
| sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nColumn, r1); |
| pushOntoSorter(pParse, pOrderBy, p, r1); |
| sqlite3ReleaseTempReg(pParse, r1); |
| }else if( eDest==SRT_Coroutine ){ |
| sqlite3VdbeAddOp1(v, OP_Yield, pDest->iParm); |
| }else{ |
| sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, nColumn); |
| sqlite3ExprCacheAffinityChange(pParse, regResult, nColumn); |
| } |
| break; |
| } |
| |
| #if !defined(SQLITE_OMIT_TRIGGER) |
| /* Discard the results. This is used for SELECT statements inside |
| ** the body of a TRIGGER. The purpose of such selects is to call |
| ** user-defined functions that have side effects. We do not care |
| ** about the actual results of the select. |
| */ |
| default: { |
| assert( eDest==SRT_Discard ); |
| break; |
| } |
| #endif |
| } |
| |
| /* Jump to the end of the loop if the LIMIT is reached. Except, if |
| ** there is a sorter, in which case the sorter has already limited |
| ** the output for us. |
| */ |
| if( pOrderBy==0 && p->iLimit ){ |
| sqlite3VdbeAddOp3(v, OP_IfZero, p->iLimit, iBreak, -1); |
| } |
| } |
| |
| /* |
| ** Given an expression list, generate a KeyInfo structure that records |
| ** the collating sequence for each expression in that expression list. |
| ** |
| ** If the ExprList is an ORDER BY or GROUP BY clause then the resulting |
| ** KeyInfo structure is appropriate for initializing a virtual index to |
| ** implement that clause. If the ExprList is the result set of a SELECT |
| ** then the KeyInfo structure is appropriate for initializing a virtual |
| ** index to implement a DISTINCT test. |
| ** |
| ** Space to hold the KeyInfo structure is obtain from malloc. The calling |
| ** function is responsible for seeing that this structure is eventually |
| ** freed. Add the KeyInfo structure to the P4 field of an opcode using |
| ** P4_KEYINFO_HANDOFF is the usual way of dealing with this. |
| */ |
| static KeyInfo *keyInfoFromExprList(Parse *pParse, ExprList *pList){ |
| sqlite3 *db = pParse->db; |
| int nExpr; |
| KeyInfo *pInfo; |
| struct ExprList_item *pItem; |
| int i; |
| |
| nExpr = pList->nExpr; |
| pInfo = sqlite3DbMallocZero(db, sizeof(*pInfo) + nExpr*(sizeof(CollSeq*)+1) ); |
| if( pInfo ){ |
| pInfo->aSortOrder = (u8*)&pInfo->aColl[nExpr]; |
| pInfo->nField = (u16)nExpr; |
| pInfo->enc = ENC(db); |
| pInfo->db = db; |
| for(i=0, pItem=pList->a; i<nExpr; i++, pItem++){ |
| CollSeq *pColl; |
| pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr); |
| if( !pColl ){ |
| pColl = db->pDfltColl; |
| } |
| pInfo->aColl[i] = pColl; |
| pInfo->aSortOrder[i] = pItem->sortOrder; |
| } |
| } |
| return pInfo; |
| } |
| |
| #ifndef SQLITE_OMIT_COMPOUND_SELECT |
| /* |
| ** Name of the connection operator, used for error messages. |
| */ |
| static const char *selectOpName(int id){ |
| char *z; |
| switch( id ){ |
| case TK_ALL: z = "UNION ALL"; break; |
| case TK_INTERSECT: z = "INTERSECT"; break; |
| case TK_EXCEPT: z = "EXCEPT"; break; |
| default: z = "UNION"; break; |
| } |
| return z; |
| } |
| #endif /* SQLITE_OMIT_COMPOUND_SELECT */ |
| |
| #ifndef SQLITE_OMIT_EXPLAIN |
| /* |
| ** Unless an "EXPLAIN QUERY PLAN" command is being processed, this function |
| ** is a no-op. Otherwise, it adds a single row of output to the EQP result, |
| ** where the caption is of the form: |
| ** |
| ** "USE TEMP B-TREE FOR xxx" |
| ** |
| ** where xxx is one of "DISTINCT", "ORDER BY" or "GROUP BY". Exactly which |
| ** is determined by the zUsage argument. |
| */ |
| static void explainTempTable(Parse *pParse, const char *zUsage){ |
| if( pParse->explain==2 ){ |
| Vdbe *v = pParse->pVdbe; |
| char *zMsg = sqlite3MPrintf(pParse->db, "USE TEMP B-TREE FOR %s", zUsage); |
| sqlite3VdbeAddOp4(v, OP_Explain, pParse->iSelectId, 0, 0, zMsg, P4_DYNAMIC); |
| } |
| } |
| |
| /* |
| ** Assign expression b to lvalue a. A second, no-op, version of this macro |
| ** is provided when SQLITE_OMIT_EXPLAIN is defined. This allows the code |
| ** in sqlite3Select() to assign values to structure member variables that |
| ** only exist if SQLITE_OMIT_EXPLAIN is not defined without polluting the |
| ** code with #ifndef directives. |
| */ |
| # define explainSetInteger(a, b) a = b |
| |
| #else |
| /* No-op versions of the explainXXX() functions and macros. */ |
| # define explainTempTable(y,z) |
| # define explainSetInteger(y,z) |
| #endif |
| |
| #if !defined(SQLITE_OMIT_EXPLAIN) && !defined(SQLITE_OMIT_COMPOUND_SELECT) |
| /* |
| ** Unless an "EXPLAIN QUERY PLAN" command is being processed, this function |
| ** is a no-op. Otherwise, it adds a single row of output to the EQP result, |
| ** where the caption is of one of the two forms: |
| ** |
| ** "COMPOSITE SUBQUERIES iSub1 and iSub2 (op)" |
| ** "COMPOSITE SUBQUERIES iSub1 and iSub2 USING TEMP B-TREE (op)" |
| ** |
| ** where iSub1 and iSub2 are the integers passed as the corresponding |
| ** function parameters, and op is the text representation of the parameter |
| ** of the same name. The parameter "op" must be one of TK_UNION, TK_EXCEPT, |
| ** TK_INTERSECT or TK_ALL. The first form is used if argument bUseTmp is |
| ** false, or the second form if it is true. |
| */ |
| static void explainComposite( |
| Parse *pParse, /* Parse context */ |
| int op, /* One of TK_UNION, TK_EXCEPT etc. */ |
| int iSub1, /* Subquery id 1 */ |
| int iSub2, /* Subquery id 2 */ |
| int bUseTmp /* True if a temp table was used */ |
| ){ |
| assert( op==TK_UNION || op==TK_EXCEPT || op==TK_INTERSECT || op==TK_ALL ); |
| if( pParse->explain==2 ){ |
| Vdbe *v = pParse->pVdbe; |
| char *zMsg = sqlite3MPrintf( |
| pParse->db, "COMPOUND SUBQUERIES %d AND %d %s(%s)", iSub1, iSub2, |
| bUseTmp?"USING TEMP B-TREE ":"", selectOpName(op) |
| ); |
| sqlite3VdbeAddOp4(v, OP_Explain, pParse->iSelectId, 0, 0, zMsg, P4_DYNAMIC); |
| } |
| } |
| #else |
| /* No-op versions of the explainXXX() functions and macros. */ |
| # define explainComposite(v,w,x,y,z) |
| #endif |
| |
| /* |
| ** If the inner loop was generated using a non-null pOrderBy argument, |
| ** then the results were placed in a sorter. After the loop is terminated |
| ** we need to run the sorter and output the results. The following |
| ** routine generates the code needed to do that. |
| */ |
| static void generateSortTail( |
| Parse *pParse, /* Parsing context */ |
| Select *p, /* The SELECT statement */ |
| Vdbe *v, /* Generate code into this VDBE */ |
| int nColumn, /* Number of columns of data */ |
| SelectDest *pDest /* Write the sorted results here */ |
| ){ |
| int addrBreak = sqlite3VdbeMakeLabel(v); /* Jump here to exit loop */ |
| int addrContinue = sqlite3VdbeMakeLabel(v); /* Jump here for next cycle */ |
| int addr; |
| int iTab; |
| int pseudoTab = 0; |
| ExprList *pOrderBy = p->pOrderBy; |
| |
| int eDest = pDest->eDest; |
| int iParm = pDest->iParm; |
| |
| int regRow; |
| int regRowid; |
| |
| iTab = pOrderBy->iECursor; |
| regRow = sqlite3GetTempReg(pParse); |
| if( eDest==SRT_Output || eDest==SRT_Coroutine ){ |
| pseudoTab = pParse->nTab++; |
| sqlite3VdbeAddOp3(v, OP_OpenPseudo, pseudoTab, regRow, nColumn); |
| regRowid = 0; |
| }else{ |
| regRowid = sqlite3GetTempReg(pParse); |
| } |
| addr = 1 + sqlite3VdbeAddOp2(v, OP_Sort, iTab, addrBreak); |
| codeOffset(v, p, addrContinue); |
| sqlite3VdbeAddOp3(v, OP_Column, iTab, pOrderBy->nExpr + 1, regRow); |
| switch( eDest ){ |
| case SRT_Table: |
| case SRT_EphemTab: { |
| testcase( eDest==SRT_Table ); |
| testcase( eDest==SRT_EphemTab ); |
| sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, regRowid); |
| sqlite3VdbeAddOp3(v, OP_Insert, iParm, regRow, regRowid); |
| sqlite3VdbeChangeP5(v, OPFLAG_APPEND); |
| break; |
| } |
| #ifndef SQLITE_OMIT_SUBQUERY |
| case SRT_Set: { |
| assert( nColumn==1 ); |
| sqlite3VdbeAddOp4(v, OP_MakeRecord, regRow, 1, regRowid, &p->affinity, 1); |
| sqlite3ExprCacheAffinityChange(pParse, regRow, 1); |
| sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, regRowid); |
| break; |
| } |
| case SRT_Mem: { |
| assert( nColumn==1 ); |
| sqlite3ExprCodeMove(pParse, regRow, iParm, 1); |
| /* The LIMIT clause will terminate the loop for us */ |
| break; |
| } |
| #endif |
| default: { |
| int i; |
| assert( eDest==SRT_Output || eDest==SRT_Coroutine ); |
| testcase( eDest==SRT_Output ); |
| testcase( eDest==SRT_Coroutine ); |
| for(i=0; i<nColumn; i++){ |
| assert( regRow!=pDest->iMem+i ); |
| sqlite3VdbeAddOp3(v, OP_Column, pseudoTab, i, pDest->iMem+i); |
| if( i==0 ){ |
| sqlite3VdbeChangeP5(v, OPFLAG_CLEARCACHE); |
| } |
| } |
| if( eDest==SRT_Output ){ |
| sqlite3VdbeAddOp2(v, OP_ResultRow, pDest->iMem, nColumn); |
| sqlite3ExprCacheAffinityChange(pParse, pDest->iMem, nColumn); |
| }else{ |
| sqlite3VdbeAddOp1(v, OP_Yield, pDest->iParm); |
| } |
| break; |
| } |
| } |
| sqlite3ReleaseTempReg(pParse, regRow); |
| sqlite3ReleaseTempReg(pParse, regRowid); |
| |
| /* The bottom of the loop |
| */ |
| sqlite3VdbeResolveLabel(v, addrContinue); |
| sqlite3VdbeAddOp2(v, OP_Next, iTab, addr); |
| sqlite3VdbeResolveLabel(v, addrBreak); |
| if( eDest==SRT_Output || eDest==SRT_Coroutine ){ |
| sqlite3VdbeAddOp2(v, OP_Close, pseudoTab, 0); |
| } |
| } |
| |
| /* |
| ** Return a pointer to a string containing the 'declaration type' of the |
| ** expression pExpr. The string may be treated as static by the caller. |
| ** |
| ** The declaration type is the exact datatype definition extracted from the |
| ** original CREATE TABLE statement if the expression is a column. The |
| ** declaration type for a ROWID field is INTEGER. Exactly when an expression |
| ** is considered a column can be complex in the presence of subqueries. The |
| ** result-set expression in all of the following SELECT statements is |
| ** considered a column by this function. |
| ** |
| ** SELECT col FROM tbl; |
| ** SELECT (SELECT col FROM tbl; |
| ** SELECT (SELECT col FROM tbl); |
| ** SELECT abc FROM (SELECT col AS abc FROM tbl); |
| ** |
| ** The declaration type for any expression other than a column is NULL. |
| */ |
| static const char *columnType( |
| NameContext *pNC, |
| Expr *pExpr, |
| const char **pzOriginDb, |
| const char **pzOriginTab, |
| const char **pzOriginCol |
| ){ |
| char const *zType = 0; |
| char const *zOriginDb = 0; |
| char const *zOriginTab = 0; |
| char const *zOriginCol = 0; |
| int j; |
| if( NEVER(pExpr==0) || pNC->pSrcList==0 ) return 0; |
| |
| switch( pExpr->op ){ |
| case TK_AGG_COLUMN: |
| case TK_COLUMN: { |
| /* The expression is a column. Locate the table the column is being |
| ** extracted from in NameContext.pSrcList. This table may be real |
| ** database table or a subquery. |
| */ |
| Table *pTab = 0; /* Table structure column is extracted from */ |
| Select *pS = 0; /* Select the column is extracted from */ |
| int iCol = pExpr->iColumn; /* Index of column in pTab */ |
| testcase( pExpr->op==TK_AGG_COLUMN ); |
| testcase( pExpr->op==TK_COLUMN ); |
| while( pNC && !pTab ){ |
| SrcList *pTabList = pNC->pSrcList; |
| for(j=0;j<pTabList->nSrc && pTabList->a[j].iCursor!=pExpr->iTable;j++); |
| if( j<pTabList->nSrc ){ |
| pTab = pTabList->a[j].pTab; |
| pS = pTabList->a[j].pSelect; |
| }else{ |
| pNC = pNC->pNext; |
| } |
| } |
| |
| if( pTab==0 ){ |
| /* At one time, code such as "SELECT new.x" within a trigger would |
| ** cause this condition to run. Since then, we have restructured how |
| ** trigger code is generated and so this condition is no longer |
| ** possible. However, it can still be true for statements like |
| ** the following: |
| ** |
| ** CREATE TABLE t1(col INTEGER); |
| ** SELECT (SELECT t1.col) FROM FROM t1; |
| ** |
| ** when columnType() is called on the expression "t1.col" in the |
| ** sub-select. In this case, set the column type to NULL, even |
| ** though it should really be "INTEGER". |
| ** |
| ** This is not a problem, as the column type of "t1.col" is never |
| ** used. When columnType() is called on the expression |
| ** "(SELECT t1.col)", the correct type is returned (see the TK_SELECT |
| ** branch below. */ |
| break; |
| } |
| |
| assert( pTab && pExpr->pTab==pTab ); |
| if( pS ){ |
| /* The "table" is actually a sub-select or a view in the FROM clause |
| ** of the SELECT statement. Return the declaration type and origin |
| ** data for the result-set column of the sub-select. |
| */ |
| if( iCol>=0 && ALWAYS(iCol<pS->pEList->nExpr) ){ |
| /* If iCol is less than zero, then the expression requests the |
| ** rowid of the sub-select or view. This expression is legal (see |
| ** test case misc2.2.2) - it always evaluates to NULL. |
| */ |
| NameContext sNC; |
| Expr *p = pS->pEList->a[iCol].pExpr; |
| sNC.pSrcList = pS->pSrc; |
| sNC.pNext = pNC; |
| sNC.pParse = pNC->pParse; |
| zType = columnType(&sNC, p, &zOriginDb, &zOriginTab, &zOriginCol); |
| } |
| }else if( ALWAYS(pTab->pSchema) ){ |
| /* A real table */ |
| assert( !pS ); |
| if( iCol<0 ) iCol = pTab->iPKey; |
| assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) ); |
| if( iCol<0 ){ |
| zType = "INTEGER"; |
| zOriginCol = "rowid"; |
| }else{ |
| zType = pTab->aCol[iCol].zType; |
| zOriginCol = pTab->aCol[iCol].zName; |
| } |
| zOriginTab = pTab->zName; |
| if( pNC->pParse ){ |
| int iDb = sqlite3SchemaToIndex(pNC->pParse->db, pTab->pSchema); |
| zOriginDb = pNC->pParse->db->aDb[iDb].zName; |
| } |
| } |
| break; |
| } |
| #ifndef SQLITE_OMIT_SUBQUERY |
| case TK_SELECT: { |
| /* The expression is a sub-select. Return the declaration type and |
| ** origin info for the single column in the result set of the SELECT |
| ** statement. |
| */ |
| NameContext sNC; |
| Select *pS = pExpr->x.pSelect; |
| Expr *p = pS->pEList->a[0].pExpr; |
| assert( ExprHasProperty(pExpr, EP_xIsSelect) ); |
| sNC.pSrcList = pS->pSrc; |
| sNC.pNext = pNC; |
| sNC.pParse = pNC->pParse; |
| zType = columnType(&sNC, p, &zOriginDb, &zOriginTab, &zOriginCol); |
| break; |
| } |
| #endif |
| } |
| |
| if( pzOriginDb ){ |
| assert( pzOriginTab && pzOriginCol ); |
| *pzOriginDb = zOriginDb; |
| *pzOriginTab = zOriginTab; |
| *pzOriginCol = zOriginCol; |
| } |
| return zType; |
| } |
| |
| /* |
| ** Generate code that will tell the VDBE the declaration types of columns |
| ** in the result set. |
| */ |
| static void generateColumnTypes( |
| Parse *pParse, /* Parser context */ |
| SrcList *pTabList, /* List of tables */ |
| ExprList *pEList /* Expressions defining the result set */ |
| ){ |
| #ifndef SQLITE_OMIT_DECLTYPE |
| Vdbe *v = pParse->pVdbe; |
| int i; |
| NameContext sNC; |
| sNC.pSrcList = pTabList; |
| sNC.pParse = pParse; |
| for(i=0; i<pEList->nExpr; i++){ |
| Expr *p = pEList->a[i].pExpr; |
| const char *zType; |
| #ifdef SQLITE_ENABLE_COLUMN_METADATA |
| const char *zOrigDb = 0; |
| const char *zOrigTab = 0; |
| const char *zOrigCol = 0; |
| zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol); |
| |
| /* The vdbe must make its own copy of the column-type and other |
| ** column specific strings, in case the schema is reset before this |
| ** virtual machine is deleted. |
| */ |
| sqlite3VdbeSetColName(v, i, COLNAME_DATABASE, zOrigDb, SQLITE_TRANSIENT); |
| sqlite3VdbeSetColName(v, i, COLNAME_TABLE, zOrigTab, SQLITE_TRANSIENT); |
| sqlite3VdbeSetColName(v, i, COLNAME_COLUMN, zOrigCol, SQLITE_TRANSIENT); |
| #else |
| zType = columnType(&sNC, p, 0, 0, 0); |
| #endif |
| sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, SQLITE_TRANSIENT); |
| } |
| #endif /* SQLITE_OMIT_DECLTYPE */ |
| } |
| |
| /* |
| ** Generate code that will tell the VDBE the names of columns |
| ** in the result set. This information is used to provide the |
| ** azCol[] values in the callback. |
| */ |
| static void generateColumnNames( |
| Parse *pParse, /* Parser context */ |
| SrcList *pTabList, /* List of tables */ |
| ExprList *pEList /* Expressions defining the result set */ |
| ){ |
| Vdbe *v = pParse->pVdbe; |
| int i, j; |
| sqlite3 *db = pParse->db; |
| int fullNames, shortNames; |
| |
| #ifndef SQLITE_OMIT_EXPLAIN |
| /* If this is an EXPLAIN, skip this step */ |
| if( pParse->explain ){ |
| return; |
| } |
| #endif |
| |
| if( pParse->colNamesSet || NEVER(v==0) || db->mallocFailed ) return; |
| pParse->colNamesSet = 1; |
| fullNames = (db->flags & SQLITE_FullColNames)!=0; |
| shortNames = (db->flags & SQLITE_ShortColNames)!=0; |
| sqlite3VdbeSetNumCols(v, pEList->nExpr); |
| for(i=0; i<pEList->nExpr; i++){ |
| Expr *p; |
| p = pEList->a[i].pExpr; |
| if( NEVER(p==0) ) continue; |
| if( pEList->a[i].zName ){ |
| char *zName = pEList->a[i].zName; |
| sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_TRANSIENT); |
| }else if( (p->op==TK_COLUMN || p->op==TK_AGG_COLUMN) && pTabList ){ |
| Table *pTab; |
| char *zCol; |
| int iCol = p->iColumn; |
| for(j=0; ALWAYS(j<pTabList->nSrc); j++){ |
| if( pTabList->a[j].iCursor==p->iTable ) break; |
| } |
| assert( j<pTabList->nSrc ); |
| pTab = pTabList->a[j].pTab; |
| if( iCol<0 ) iCol = pTab->iPKey; |
| assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) ); |
| if( iCol<0 ){ |
| zCol = "rowid"; |
| }else{ |
| zCol = pTab->aCol[iCol].zName; |
| } |
| if( !shortNames && !fullNames ){ |
| sqlite3VdbeSetColName(v, i, COLNAME_NAME, |
| sqlite3DbStrDup(db, pEList->a[i].zSpan), SQLITE_DYNAMIC); |
| }else if( fullNames ){ |
| char *zName = 0; |
| zName = sqlite3MPrintf(db, "%s.%s", pTab->zName, zCol); |
| sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_DYNAMIC); |
| }else{ |
| sqlite3VdbeSetColName(v, i, COLNAME_NAME, zCol, SQLITE_TRANSIENT); |
| } |
| }else{ |
| sqlite3VdbeSetColName(v, i, COLNAME_NAME, |
| sqlite3DbStrDup(db, pEList->a[i].zSpan), SQLITE_DYNAMIC); |
| } |
| } |
| generateColumnTypes(pParse, pTabList, pEList); |
| } |
| |
| /* |
| ** Given a an expression list (which is really the list of expressions |
| ** that form the result set of a SELECT statement) compute appropriate |
| ** column names for a table that would hold the expression list. |
| ** |
| ** All column names will be unique. |
| ** |
| ** Only the column names are computed. Column.zType, Column.zColl, |
| ** and other fields of Column are zeroed. |
| ** |
| ** Return SQLITE_OK on success. If a memory allocation error occurs, |
| ** store NULL in *paCol and 0 in *pnCol and return SQLITE_NOMEM. |
| */ |
| static int selectColumnsFromExprList( |
| Parse *pParse, /* Parsing context */ |
| ExprList *pEList, /* Expr list from which to derive column names */ |
| int *pnCol, /* Write the number of columns here */ |
| Column **paCol /* Write the new column list here */ |
| ){ |
| sqlite3 *db = pParse->db; /* Database connection */ |
| int i, j; /* Loop counters */ |
| int cnt; /* Index added to make the name unique */ |
| Column *aCol, *pCol; /* For looping over result columns */ |
| int nCol; /* Number of columns in the result set */ |
| Expr *p; /* Expression for a single result column */ |
| char *zName; /* Column name */ |
| int nName; /* Size of name in zName[] */ |
| |
| *pnCol = nCol = pEList->nExpr; |
| aCol = *paCol = sqlite3DbMallocZero(db, sizeof(aCol[0])*nCol); |
| if( aCol==0 ) return SQLITE_NOMEM; |
| for(i=0, pCol=aCol; i<nCol; i++, pCol++){ |
| /* Get an appropriate name for the column |
| */ |
| p = 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); |
| }else{ |
| Expr *pColExpr = p; /* The expression that is the result column name */ |
| Table *pTab; /* Table associated with this expression */ |
| while( pColExpr->op==TK_DOT ) pColExpr = pColExpr->pRight; |
| if( pColExpr->op==TK_COLUMN && ALWAYS(pColExpr->pTab!=0) ){ |
| /* For columns use the column name name */ |
| int iCol = pColExpr->iColumn; |
| pTab = pColExpr->pTab; |
| if( iCol<0 ) iCol = pTab->iPKey; |
| zName = sqlite3MPrintf(db, "%s", |
| iCol>=0 ? pTab->aCol[iCol].zName : "rowid"); |
| }else if( pColExpr->op==TK_ID ){ |
| assert( !ExprHasProperty(pColExpr, EP_IntValue) ); |
| zName = sqlite3MPrintf(db, "%s", pColExpr->u.zToken); |
| }else{ |
| /* Use the original text of the column expression as its name */ |
| zName = sqlite3MPrintf(db, "%s", pEList->a[i].zSpan); |
| } |
| } |
| if( db->mallocFailed ){ |
| sqlite3DbFree(db, zName); |
| break; |
| } |
| |
| /* Make sure the column name is unique. If the name is not unique, |
| ** append a integer to the name so that it becomes unique. |
| */ |
| nName = sqlite3Strlen30(zName); |
| for(j=cnt=0; j<i; j++){ |
| if( sqlite3StrICmp(aCol[j].zName, zName)==0 ){ |
| char *zNewName; |
| zName[nName] = 0; |
| zNewName = sqlite3MPrintf(db, "%s:%d", zName, ++cnt); |
| sqlite3DbFree(db, zName); |
| zName = zNewName; |
| j = -1; |
| if( zName==0 ) break; |
| } |
| } |
| pCol->zName = zName; |
| } |
| if( db->mallocFailed ){ |
| for(j=0; j<i; j++){ |
| sqlite3DbFree(db, aCol[j].zName); |
| } |
| sqlite3DbFree(db, aCol); |
| *paCol = 0; |
| *pnCol = 0; |
| return SQLITE_NOMEM; |
| } |
| return SQLITE_OK; |
| } |
| |
| /* |
| ** Add type and collation information to a column list based on |
| ** a SELECT statement. |
| ** |
| ** The column list presumably came from selectColumnNamesFromExprList(). |
| ** The column list has only names, not types or collations. This |
| ** routine goes through and adds the types and collations. |
| ** |
| ** This routine requires that all identifiers in the SELECT |
| ** statement be resolved. |
| */ |
| static void selectAddColumnTypeAndCollation( |
| Parse *pParse, /* Parsing contexts */ |
| int nCol, /* Number of columns */ |
| Column *aCol, /* List of columns */ |
| Select *pSelect /* SELECT used to determine types and collations */ |
| ){ |
| sqlite3 *db = pParse->db; |
| NameContext sNC; |
| Column *pCol; |
| CollSeq *pColl; |
| int i; |
| Expr *p; |
| struct ExprList_item *a; |
| |
| assert( pSelect!=0 ); |
| assert( (pSelect->selFlags & SF_Resolved)!=0 ); |
| assert( nCol==pSelect->pEList->nExpr || db->mallocFailed ); |
| if( db->mallocFailed ) return; |
| memset(&sNC, 0, sizeof(sNC)); |
| sNC.pSrcList = pSelect->pSrc; |
| a = pSelect->pEList->a; |
| for(i=0, pCol=aCol; i<nCol; i++, pCol++){ |
| p = a[i].pExpr; |
| pCol->zType = sqlite3DbStrDup(db, columnType(&sNC, p, 0, 0, 0)); |
| pCol->affinity = sqlite3ExprAffinity(p); |
| if( pCol->affinity==0 ) pCol->affinity = SQLITE_AFF_NONE; |
| pColl = sqlite3ExprCollSeq(pParse, p); |
| if( pColl ){ |
| pCol->zColl = sqlite3DbStrDup(db, pColl->zName); |
| } |
| } |
| } |
| |
| /* |
| ** Given a SELECT statement, generate a Table structure that describes |
| ** the result set of that SELECT. |
| */ |
| Table *sqlite3ResultSetOfSelect(Parse *pParse, Select *pSelect){ |
| Table *pTab; |
| sqlite3 *db = pParse->db; |
| int savedFlags; |
| |
| savedFlags = db->flags; |
| db->flags &= ~SQLITE_FullColNames; |
| db->flags |= SQLITE_ShortColNames; |
| sqlite3SelectPrep(pParse, pSelect, 0); |
| if( pParse->nErr ) return 0; |
| while( pSelect->pPrior ) pSelect = pSelect->pPrior; |
| db->flags = savedFlags; |
| pTab = sqlite3DbMallocZero(db, sizeof(Table) ); |
| if( pTab==0 ){ |
| return 0; |
| } |
| /* The sqlite3ResultSetOfSelect() is only used n contexts where lookaside |
| ** is disabled */ |
| assert( db->lookaside.bEnabled==0 ); |
| pTab->nRef = 1; |
| pTab->zName = 0; |
| pTab->nRowEst = 1000000; |
| selectColumnsFromExprList(pParse, pSelect->pEList, &pTab->nCol, &pTab->aCol); |
| selectAddColumnTypeAndCollation(pParse, pTab->nCol, pTab->aCol, pSelect); |
| pTab->iPKey = -1; |
| if( db->mallocFailed ){ |
| sqlite3DeleteTable(db, pTab); |
| return 0; |
| } |
| return pTab; |
| } |
| |
| /* |
| ** Get a VDBE for the given parser context. Create a new one if necessary. |
| ** If an error occurs, return NULL and leave a message in pParse. |
| */ |
| Vdbe *sqlite3GetVdbe(Parse *pParse){ |
| Vdbe *v = pParse->pVdbe; |
| if( v==0 ){ |
| v = pParse->pVdbe = sqlite3VdbeCreate(pParse->db); |
| #ifndef SQLITE_OMIT_TRACE |
| if( v ){ |
| sqlite3VdbeAddOp0(v, OP_Trace); |
| } |
| #endif |
| } |
| return v; |
| } |
| |
| |
| /* |
| ** Compute the iLimit and iOffset fields of the SELECT based on the |
| ** pLimit and pOffset expressions. pLimit and pOffset hold the expressions |
| ** that appear in the original SQL statement after the LIMIT and OFFSET |
| ** keywords. Or NULL if those keywords are omitted. iLimit and iOffset |
| ** are the integer memory register numbers for counters used to compute |
| ** the limit and offset. If there is no limit and/or offset, then |
| ** iLimit and iOffset are negative. |
| ** |
| ** This routine changes the values of iLimit and iOffset only if |
| ** a limit or offset is defined by pLimit and pOffset. iLimit and |
| ** iOffset should have been preset to appropriate default values |
| ** (usually but not always -1) prior to calling this routine. |
| ** Only if pLimit!=0 or pOffset!=0 do the limit registers get |
| ** redefined. The UNION ALL operator uses this property to force |
| ** the reuse of the same limit and offset registers across multiple |
| ** SELECT statements. |
| */ |
| static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){ |
| Vdbe *v = 0; |
| int iLimit = 0; |
| int iOffset; |
| int addr1, n; |
| if( p->iLimit ) return; |
| |
| /* |
| ** "LIMIT -1" always shows all rows. There is some |
| ** contraversy about what the correct behavior should be. |
| ** The current implementation interprets "LIMIT 0" to mean |
| ** no rows. |
| */ |
| sqlite3ExprCacheClear(pParse); |
| assert( p->pOffset==0 || p->pLimit!=0 ); |
| if( p->pLimit ){ |
| p->iLimit = iLimit = ++pParse->nMem; |
| v = sqlite3GetVdbe(pParse); |
| if( NEVER(v==0) ) return; /* VDBE should have already been allocated */ |
| if( sqlite3ExprIsInteger(p->pLimit, &n) ){ |
| sqlite3VdbeAddOp2(v, OP_Integer, n, iLimit); |
| VdbeComment((v, "LIMIT counter")); |
| if( n==0 ){ |
| sqlite3VdbeAddOp2(v, OP_Goto, 0, iBreak); |
| }else{ |
| if( p->nSelectRow > (double)n ) p->nSelectRow = (double)n; |
| } |
| }else{ |
| sqlite3ExprCode(pParse, p->pLimit, iLimit); |
| sqlite3VdbeAddOp1(v, OP_MustBeInt, iLimit); |
| VdbeComment((v, "LIMIT counter")); |
| sqlite3VdbeAddOp2(v, OP_IfZero, iLimit, iBreak); |
| } |
| if( p->pOffset ){ |
| p->iOffset = iOffset = ++pParse->nMem; |
| pParse->nMem++; /* Allocate an extra register for limit+offset */ |
| sqlite3ExprCode(pParse, p->pOffset, iOffset); |
| sqlite3VdbeAddOp1(v, OP_MustBeInt, iOffset); |
| VdbeComment((v, "OFFSET counter")); |
| addr1 = sqlite3VdbeAddOp1(v, OP_IfPos, iOffset); |
| sqlite3VdbeAddOp2(v, OP_Integer, 0, iOffset); |
| sqlite3VdbeJumpHere(v, addr1); |
| sqlite3VdbeAddOp3(v, OP_Add, iLimit, iOffset, iOffset+1); |
| VdbeComment((v, "LIMIT+OFFSET")); |
| addr1 = sqlite3VdbeAddOp1(v, OP_IfPos, iLimit); |
| sqlite3VdbeAddOp2(v, OP_Integer, -1, iOffset+1); |
| sqlite3VdbeJumpHere(v, addr1); |
| } |
| } |
| } |
| |
| #ifndef SQLITE_OMIT_COMPOUND_SELECT |
| /* |
| ** Return the appropriate collating sequence for the iCol-th column of |
| ** the result set for the compound-select statement "p". Return NULL if |
| ** the column has no default collating sequence. |
| ** |
| ** The collating sequence for the compound select is taken from the |
| ** left-most term of the select that has a collating sequence. |
| */ |
| static CollSeq *multiSelectCollSeq(Parse *pParse, Select *p, int iCol){ |
| CollSeq *pRet; |
| if( p->pPrior ){ |
| pRet = multiSelectCollSeq(pParse, p->pPrior, iCol); |
| }else{ |
| pRet = 0; |
| } |
| assert( iCol>=0 ); |
| if( pRet==0 && iCol<p->pEList->nExpr ){ |
| pRet = sqlite3ExprCollSeq(pParse, p->pEList->a[iCol].pExpr); |
| } |
| return pRet; |
| } |
| #endif /* SQLITE_OMIT_COMPOUND_SELECT */ |
| |
| /* Forward reference */ |
| static int multiSelectOrderBy( |
| Parse *pParse, /* Parsing context */ |
| Select *p, /* The right-most of SELECTs to be coded */ |
| SelectDest *pDest /* What to do with query results */ |
| ); |
| |
| |
| #ifndef SQLITE_OMIT_COMPOUND_SELECT |
| /* |
| ** This routine is called to process a compound query form from |
| ** two or more separate queries using UNION, UNION ALL, EXCEPT, or |
| ** INTERSECT |
| ** |
| ** "p" points to the right-most of the two queries. the query on the |
| ** left is p->pPrior. The left query could also be a compound query |
| ** in which case this routine will be called recursively. |
| ** |
| ** The results of the total query are to be written into a destination |
| ** of type eDest with parameter iParm. |
| ** |
| ** Example 1: Consider a three-way compound SQL statement. |
| ** |
| ** SELECT a FROM t1 UNION SELECT b FROM t2 UNION SELECT c FROM t3 |
| ** |
| ** This statement is parsed up as follows: |
| ** |
| ** SELECT c FROM t3 |
| ** | |
| ** `-----> SELECT b FROM t2 |
| ** | |
| ** `------> SELECT a FROM t1 |
| ** |
| ** The arrows in the diagram above represent the Select.pPrior pointer. |
| ** So if this routine is called with p equal to the t3 query, then |
| ** pPrior will be the t2 query. p->op will be TK_UNION in this case. |
| ** |
| ** Notice that because of the way SQLite parses compound SELECTs, the |
| ** individual selects always group from left to right. |
| */ |
| static int multiSelect( |
| Parse *pParse, /* Parsing context */ |
| Select *p, /* The right-most of SELECTs to be coded */ |
| SelectDest *pDest /* What to do with query results */ |
| ){ |
| int rc = SQLITE_OK; /* Success code from a subroutine */ |
| Select *pPrior; /* Another SELECT immediately to our left */ |
| Vdbe *v; /* Generate code to this VDBE */ |
| SelectDest dest; /* Alternative data destination */ |
| Select *pDelete = 0; /* Chain of simple selects to delete */ |
| sqlite3 *db; /* Database connection */ |
| #ifndef SQLITE_OMIT_EXPLAIN |
| int iSub1; /* EQP id of left-hand query */ |
| int iSub2; /* EQP id of right-hand query */ |
| #endif |
| |
| /* Make sure there is no ORDER BY or LIMIT clause on prior SELECTs. Only |
| ** the last (right-most) SELECT in the series may have an ORDER BY or LIMIT. |
| */ |
| assert( p && p->pPrior ); /* Calling function guarantees this much */ |
| 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", |
| selectOpName(p->op)); |
| rc = 1; |
| goto multi_select_end; |
| } |
| if( pPrior->pLimit ){ |
| sqlite3ErrorMsg(pParse,"LIMIT clause should come after %s not before", |
| selectOpName(p->op)); |
| rc = 1; |
| goto multi_select_end; |
| } |
| |
| v = sqlite3GetVdbe(pParse); |
| assert( v!=0 ); /* The VDBE already created by calling function */ |
| |
| /* Create the destination temporary table if necessary |
| */ |
| if( dest.eDest==SRT_EphemTab ){ |
| assert( p->pEList ); |
| sqlite3VdbeAddOp2(v, OP_OpenEphemeral, dest.iParm, p->pEList->nExpr); |
| sqlite3VdbeChangeP5(v, BTREE_UNORDERED); |
| dest.eDest = SRT_Table; |
| } |
| |
| /* Make sure all SELECTs in the statement have the same number of elements |
| ** in their result sets. |
| */ |
| assert( p->pEList && pPrior->pEList ); |
| if( p->pEList->nExpr!=pPrior->pEList->nExpr ){ |
| sqlite3ErrorMsg(pParse, "SELECTs to the left and right of %s" |
| " do not have the same number of result columns", selectOpName(p->op)); |
| rc = 1; |
| goto multi_select_end; |
| } |
| |
| /* Compound SELECTs that have an ORDER BY clause are handled separately. |
| */ |
| if( p->pOrderBy ){ |
| return multiSelectOrderBy(pParse, p, pDest); |
| } |
| |
| /* Generate code for the left and right SELECT statements. |
| */ |
| switch( p->op ){ |
| case TK_ALL: { |
| int addr = 0; |
| int nLimit; |
| assert( !pPrior->pLimit ); |
| pPrior->pLimit = p->pLimit; |
| pPrior->pOffset = p->pOffset; |
| explainSetInteger(iSub1, pParse->iNextSelectId); |
| rc = sqlite3Select(pParse, pPrior, &dest); |
| p->pLimit = 0; |
| p->pOffset = 0; |
| if( rc ){ |
| goto multi_select_end; |
| } |
| p->pPrior = 0; |
| p->iLimit = pPrior->iLimit; |
| p->iOffset = pPrior->iOffset; |
| if( p->iLimit ){ |
| addr = sqlite3VdbeAddOp1(v, OP_IfZero, p->iLimit); |
| VdbeComment((v, "Jump ahead if LIMIT reached")); |
| } |
| explainSetInteger(iSub2, pParse->iNextSelectId); |
| rc = sqlite3Select(pParse, p, &dest); |
| testcase( rc!=SQLITE_OK ); |
| pDelete = p->pPrior; |
| p->pPrior = pPrior; |
| p->nSelectRow += pPrior->nSelectRow; |
| if( pPrior->pLimit |
| && sqlite3ExprIsInteger(pPrior->pLimit, &nLimit) |
| && p->nSelectRow > (double)nLimit |
| ){ |
| p->nSelectRow = (double)nLimit; |
| } |
| if( addr ){ |
| sqlite3VdbeJumpHere(v, addr); |
| } |
| break; |
| } |
| case TK_EXCEPT: |
| case TK_UNION: { |
| int unionTab; /* Cursor number of the temporary table holding result */ |
| u8 op = 0; /* One of the SRT_ operations to apply to self */ |
| int priorOp; /* The SRT_ operation to apply to prior selects */ |
| Expr *pLimit, *pOffset; /* Saved values of p->nLimit and p->nOffset */ |
| int addr; |
| SelectDest uniondest; |
| |
| testcase( p->op==TK_EXCEPT ); |
| testcase( p->op==TK_UNION ); |
| priorOp = SRT_Union; |
| if( dest.eDest==priorOp && ALWAYS(!p->pLimit &&!p->pOffset) ){ |
| /* 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.iParm; |
| }else{ |
| /* We will need to create our own temporary table to hold the |
| ** intermediate results. |
| */ |
| unionTab = pParse->nTab++; |
| assert( p->pOrderBy==0 ); |
| addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, unionTab, 0); |
| assert( p->addrOpenEphm[0] == -1 ); |
| p->addrOpenEphm[0] = addr; |
| p->pRightmost->selFlags |= SF_UsesEphemeral; |
| assert( p->pEList ); |
| } |
| |
| /* Code the SELECT statements to our left |
| */ |
| assert( !pPrior->pOrderBy ); |
| sqlite3SelectDestInit(&uniondest, priorOp, unionTab); |
| explainSetInteger(iSub1, pParse->iNextSelectId); |
| rc = sqlite3Select(pParse, pPrior, &uniondest); |
| if( rc ){ |
| goto multi_select_end; |
| } |
| |
| /* Code the current SELECT statement |
| */ |
| if( p->op==TK_EXCEPT ){ |
| op = SRT_Except; |
| }else{ |
| assert( p->op==TK_UNION ); |
| op = SRT_Union; |
| } |
| p->pPrior = 0; |
| pLimit = p->pLimit; |
| p->pLimit = 0; |
| pOffset = p->pOffset; |
| p->pOffset = 0; |
| uniondest.eDest = op; |
| explainSetInteger(iSub2, pParse->iNextSelectId); |
| rc = sqlite3Select(pParse, p, &uniondest); |
| testcase( rc!=SQLITE_OK ); |
| /* Query flattening in sqlite3Select() might refill p->pOrderBy. |
| ** Be sure to delete p->pOrderBy, therefore, to avoid a memory leak. */ |
| sqlite3ExprListDelete(db, p->pOrderBy); |
| pDelete = p->pPrior; |
| p->pPrior = pPrior; |
| p->pOrderBy = 0; |
| if( p->op==TK_UNION ) p->nSelectRow += pPrior->nSelectRow; |
| sqlite3ExprDelete(db, p->pLimit); |
| p->pLimit = pLimit; |
| p->pOffset = pOffset; |
| p->iLimit = 0; |
| p->iOffset = 0; |
| |
| /* Convert the data in the temporary table into whatever form |
| ** it is that we currently need. |
| */ |
| assert( unionTab==dest.iParm || dest.eDest!=priorOp ); |
| if( dest.eDest!=priorOp ){ |
| int iCont, iBreak, iStart; |
| assert( p->pEList ); |
| if( dest.eDest==SRT_Output ){ |
| Select *pFirst = p; |
| while( pFirst->pPrior ) pFirst = pFirst->pPrior; |
| generateColumnNames(pParse, 0, pFirst->pEList); |
| } |
| iBreak = sqlite3VdbeMakeLabel(v); |
| iCont = sqlite3VdbeMakeLabel(v); |
| computeLimitRegisters(pParse, p, iBreak); |
| sqlite3VdbeAddOp2(v, OP_Rewind, unionTab, iBreak); |
| iStart = sqlite3VdbeCurrentAddr(v); |
| selectInnerLoop(pParse, p, p->pEList, unionTab, p->pEList->nExpr, |
| 0, -1, &dest, iCont, iBreak); |
| sqlite3VdbeResolveLabel(v, iCont); |
| sqlite3VdbeAddOp2(v, OP_Next, unionTab, iStart); |
| sqlite3VdbeResolveLabel(v, iBreak); |
| sqlite3VdbeAddOp2(v, OP_Close, unionTab, 0); |
| } |
| break; |
| } |
| default: assert( p->op==TK_INTERSECT ); { |
| int tab1, tab2; |
| int iCont, iBreak, iStart; |
| Expr *pLimit, *pOffset; |
| int addr; |
| SelectDest intersectdest; |
| int r1; |
| |
| /* INTERSECT is different from the others since it requires |
| ** two temporary tables. Hence it has its own case. Begin |
| ** by allocating the tables we will need. |
| */ |
| tab1 = pParse->nTab++; |
| tab2 = pParse->nTab++; |
| assert( p->pOrderBy==0 ); |
| |
| addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab1, 0); |
| assert( p->addrOpenEphm[0] == -1 ); |
| p->addrOpenEphm[0] = addr; |
| p->pRightmost->selFlags |= SF_UsesEphemeral; |
| assert( p->pEList ); |
| |
| /* Code the SELECTs to our left into temporary table "tab1". |
| */ |
| sqlite3SelectDestInit(&intersectdest, SRT_Union, tab1); |
| explainSetInteger(iSub1, pParse->iNextSelectId); |
| rc = sqlite3Select(pParse, pPrior, &intersectdest); |
| if( rc ){ |
| goto multi_select_end; |
| } |
| |
| /* Code the current SELECT into temporary table "tab2" |
| */ |
| addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab2, 0); |
| assert( p->addrOpenEphm[1] == -1 ); |
| p->addrOpenEphm[1] = addr; |
| p->pPrior = 0; |
| pLimit = p->pLimit; |
| p->pLimit = 0; |
| pOffset = p->pOffset; |
| p->pOffset = 0; |
| intersectdest.iParm = tab2; |
| explainSetInteger(iSub2, pParse->iNextSelectId); |
| rc = sqlite3Select(pParse, p, &intersectdest); |
| testcase( rc!=SQLITE_OK ); |
| pDelete = p->pPrior; |
| p->pPrior = pPrior; |
| if( p->nSelectRow>pPrior->nSelectRow ) p->nSelectRow = pPrior->nSelectRow; |
| sqlite3ExprDelete(db, p->pLimit); |
| p->pLimit = pLimit; |
| p->pOffset = pOffset; |
| |
| /* Generate code to take the intersection of the two temporary |
| ** tables. |
| */ |
| assert( p->pEList ); |
| if( dest.eDest==SRT_Output ){ |
| Select *pFirst = p; |
| while( pFirst->pPrior ) pFirst = pFirst->pPrior; |
| generateColumnNames(pParse, 0, pFirst->pEList); |
| } |
| iBreak = sqlite3VdbeMakeLabel(v); |
| iCont = sqlite3VdbeMakeLabel(v); |
| computeLimitRegisters(pParse, p, iBreak); |
| sqlite3VdbeAddOp2(v, OP_Rewind, tab1, iBreak); |
| r1 = sqlite3GetTempReg(pParse); |
| iStart = sqlite3VdbeAddOp2(v, OP_RowKey, tab1, r1); |
| sqlite3VdbeAddOp4Int(v, OP_NotFound, tab2, iCont, r1, 0); |
| sqlite3ReleaseTempReg(pParse, r1); |
| selectInnerLoop(pParse, p, p->pEList, tab1, p->pEList->nExpr, |
| 0, -1, &dest, iCont, iBreak); |
| sqlite3VdbeResolveLabel(v, iCont); |
| sqlite3VdbeAddOp2(v, OP_Next, tab1, iStart); |
| sqlite3VdbeResolveLabel(v, iBreak); |
| sqlite3VdbeAddOp2(v, OP_Close, tab2, 0); |
| sqlite3VdbeAddOp2(v, OP_Close, tab1, 0); |
| break; |
| } |
| } |
| |
| explainComposite(pParse, p->op, iSub1, iSub2, p->op!=TK_ALL); |
| |
| /* Compute collating sequences used by |
| ** temporary tables needed to implement the compound select. |
| ** Attach the KeyInfo structure to all temporary tables. |
| ** |
| ** This section is run by the right-most SELECT statement only. |
| ** SELECT statements to the left always skip this part. The right-most |
| ** SELECT might also skip this part if it has no ORDER BY clause and |
| ** no temp tables are required. |
| */ |
| if( p->selFlags & SF_UsesEphemeral ){ |
| int i; /* Loop counter */ |
| KeyInfo *pKeyInfo; /* Collating sequence for the result set */ |
| Select *pLoop; /* For looping through SELECT statements */ |
| CollSeq **apColl; /* For looping through pKeyInfo->aColl[] */ |
| int nCol; /* Number of columns in result set */ |
| |
| assert( p->pRightmost==p ); |
| nCol = p->pEList->nExpr; |
| pKeyInfo = sqlite3DbMallocZero(db, |
| sizeof(*pKeyInfo)+nCol*(sizeof(CollSeq*) + 1)); |
| if( !pKeyInfo ){ |
| rc = SQLITE_NOMEM; |
| goto multi_select_end; |
| } |
| |
| pKeyInfo->enc = ENC(db); |
| pKeyInfo->nField = (u16)nCol; |
| |
| for(i=0, apColl=pKeyInfo->aColl; i<nCol; i++, apColl++){ |
| *apColl = multiSelectCollSeq(pParse, p, i); |
| if( 0==*apColl ){ |
| *apColl = db->pDfltColl; |
| } |
| } |
| |
| for(pLoop=p; pLoop; pLoop=pLoop->pPrior){ |
| for(i=0; i<2; i++){ |
| int addr = pLoop->addrOpenEphm[i]; |
| if( addr<0 ){ |
| /* If [0] is unused then [1] is also unused. So we can |
| ** always safely abort as soon as the first unused slot is found */ |
| assert( pLoop->addrOpenEphm[1]<0 ); |
| break; |
| } |
| sqlite3VdbeChangeP2(v, addr, nCol); |
| sqlite3VdbeChangeP4(v, addr, (char*)pKeyInfo, P4_KEYINFO); |
| pLoop->addrOpenEphm[i] = -1; |
| } |
| } |
| sqlite3DbFree(db, pKeyInfo); |
| } |
| |
| multi_select_end: |
| pDest->iMem = dest.iMem; |
| pDest->nMem = dest.nMem; |
| sqlite3SelectDelete(db, pDelete); |
| return rc; |
| } |
| #endif /* SQLITE_OMIT_COMPOUND_SELECT */ |
| |
| /* |
| ** Code an output subroutine for a coroutine implementation of a |
| ** SELECT statment. |
| ** |
| ** The data to be output is contained in pIn->iMem. There are |
| ** pIn->nMem columns to be output. pDest is where the output should |
| ** be sent. |
| ** |
| ** regReturn is the number of the register holding the subroutine |
| ** return address. |
| ** |
| ** If regPrev>0 then it is the first register in a vector that |
| ** records the previous output. mem[regPrev] is a flag that is false |
| ** if there has been no previous output. If regPrev>0 then code is |
| ** generated to suppress duplicates. pKeyInfo is used for comparing |
| ** keys. |
| ** |
| ** If the LIMIT found in p->iLimit is reached, jump immediately to |
| ** iBreak. |
| */ |
| static int generateOutputSubroutine( |
| Parse *pParse, /* Parsing context */ |
| Select *p, /* The SELECT statement */ |
| SelectDest *pIn, /* Coroutine supplying data */ |
| SelectDest *pDest, /* Where to send the data */ |
| int regReturn, /* The return address register */ |
| int regPrev, /* Previous result register. No uniqueness if 0 */ |
| KeyInfo *pKeyInfo, /* For comparing with previous entry */ |
| int p4type, /* The p4 type for pKeyInfo */ |
| int iBreak /* Jump here if we hit the LIMIT */ |
| ){ |
| Vdbe *v = pParse->pVdbe; |
| int iContinue; |
| int addr; |
| |
| addr = sqlite3VdbeCurrentAddr(v); |
| iContinue = sqlite3VdbeMakeLabel(v); |
| |
| /* Suppress duplicates for UNION, EXCEPT, and INTERSECT |
| */ |
| if( regPrev ){ |
| int j1, j2; |
| j1 = sqlite3VdbeAddOp1(v, OP_IfNot, regPrev); |
| j2 = sqlite3VdbeAddOp4(v, OP_Compare, pIn->iMem, regPrev+1, pIn->nMem, |
| (char*)pKeyInfo, p4type); |
| sqlite3VdbeAddOp3(v, OP_Jump, j2+2, iContinue, j2+2); |
| sqlite3VdbeJumpHere(v, j1); |
| sqlite3ExprCodeCopy(pParse, pIn->iMem, regPrev+1, pIn->nMem); |
| sqlite3VdbeAddOp2(v, OP_Integer, 1, regPrev); |
| } |
| if( pParse->db->mallocFailed ) return 0; |
| |
| /* Suppress the the first OFFSET entries if there is an OFFSET clause |
| */ |
| codeOffset(v, p, iContinue); |
| |
| switch( pDest->eDest ){ |
| /* Store the result as data using a unique key. |
| */ |
| case SRT_Table: |
| case SRT_EphemTab: { |
| int r1 = sqlite3GetTempReg(pParse); |
| int r2 = sqlite3GetTempReg(pParse); |
| testcase( pDest->eDest==SRT_Table ); |
| testcase( pDest->eDest==SRT_EphemTab ); |
| sqlite3VdbeAddOp3(v, OP_MakeRecord, pIn->iMem, pIn->nMem, r1); |
| sqlite3VdbeAddOp2(v, OP_NewRowid, pDest->iParm, r2); |
| sqlite3VdbeAddOp3(v, OP_Insert, pDest->iParm, r1, r2); |
| sqlite3VdbeChangeP5(v, OPFLAG_APPEND); |
| sqlite3ReleaseTempReg(pParse, r2); |
| sqlite3ReleaseTempReg(pParse, r1); |
| break; |
| } |
| |
| #ifndef SQLITE_OMIT_SUBQUERY |
| /* If we are creating a set for an "expr IN (SELECT ...)" construct, |
| ** then there should be a single item on the stack. Write this |
| ** item into the set table with bogus data. |
| */ |
| case SRT_Set: { |
| int r1; |
| assert( pIn->nMem==1 ); |
| p->affinity = |
| sqlite3CompareAffinity(p->pEList->a[0].pExpr, pDest->affinity); |
| r1 = sqlite3GetTempReg(pParse); |
| sqlite3VdbeAddOp4(v, OP_MakeRecord, pIn->iMem, 1, r1, &p->affinity, 1); |
| sqlite3ExprCacheAffinityChange(pParse, pIn->iMem, 1); |
| sqlite3VdbeAddOp2(v, OP_IdxInsert, pDest->iParm, r1); |
| sqlite3ReleaseTempReg(pParse, r1); |
| break; |
| } |
| |
| #if 0 /* Never occurs on an ORDER BY query */ |
| /* If any row exist in the result set, record that fact and abort. |
| */ |
| case SRT_Exists: { |
| sqlite3VdbeAddOp2(v, OP_Integer, 1, pDest->iParm); |
| /* The LIMIT clause will terminate the loop for us */ |
| break; |
| } |
| #endif |
| |
| /* If this is a scalar select that is part of an expression, then |
| ** store the results in the appropriate memory cell and break out |
| ** of the scan loop. |
| */ |
| case SRT_Mem: { |
| assert( pIn->nMem==1 ); |
| sqlite3ExprCodeMove(pParse, pIn->iMem, pDest->iParm, 1); |
| /* The LIMIT clause will jump out of the loop for us */ |
| break; |
| } |
| #endif /* #ifndef SQLITE_OMIT_SUBQUERY */ |
| |
| /* The results are stored in a sequence of registers |
| ** starting at pDest->iMem. Then the co-routine yields. |
| */ |
| case SRT_Coroutine: { |
| if( pDest->iMem==0 ){ |
| pDest->iMem = sqlite3GetTempRange(pParse, pIn->nMem); |
| pDest->nMem = pIn->nMem; |
| } |
| sqlite3ExprCodeMove(pParse, pIn->iMem, pDest->iMem, pDest->nMem); |
| sqlite3VdbeAddOp1(v, OP_Yield, pDest->iParm); |
| break; |
| } |
| |
| /* If none of the above, then the result destination must be |
| ** SRT_Output. This routine is never called with any other |
| ** destination other than the ones handled above or SRT_Output. |
| ** |
| ** For SRT_Output, results are stored in a sequence of registers. |
| ** Then the OP_ResultRow opcode is used to cause sqlite3_step() to |
| ** return the next row of result. |
| */ |
| default: { |
| assert( pDest->eDest==SRT_Output ); |
| sqlite3VdbeAddOp2(v, OP_ResultRow, pIn->iMem, pIn->nMem); |
| sqlite3ExprCacheAffinityChange(pParse, pIn->iMem, pIn->nMem); |
| break; |
| } |
| } |
| |
| /* Jump to the end of the loop if the LIMIT is reached. |
| */ |
| if( p->iLimit ){ |
| sqlite3VdbeAddOp3(v, OP_IfZero, p->iLimit, iBreak, -1); |
| } |
| |
| /* Generate the subroutine return |
| */ |
| sqlite3VdbeResolveLabel(v, iContinue); |
| sqlite3VdbeAddOp1(v, OP_Return, regReturn); |
| |
| return addr; |
| } |
| |
| /* |
| ** Alternative compound select code generator for cases when there |
| ** is an ORDER BY clause. |
| ** |
| ** We assume a query of the following form: |
| ** |
| ** <selectA> <operator> <selectB> ORDER BY <orderbylist> |
| ** |
| ** <operator> is one of UNION ALL, UNION, EXCEPT, or INTERSECT. The idea |
| ** is to code both <selectA> and <selectB> with the ORDER BY clause as |
| ** co-routines. Then run the co-routines in parallel and merge the results |
| ** into the output. In addition to the two coroutines (called selectA and |
| ** selectB) there are 7 subroutines: |
| ** |
| ** outA: Move the output of the selectA coroutine into the output |
| ** of the compound query. |
| ** |
| ** outB: Move the output of the selectB coroutine into the output |
| ** of the compound query. (Only generated for UNION and |
| ** UNION ALL. EXCEPT and INSERTSECT never output a row that |
| ** appears only in B.) |
| ** |
| ** AltB: Called when there is data from both coroutines and A<B. |
| ** |
| ** AeqB: Called when there is data from both coroutines and A==B. |
| ** |
| ** AgtB: Called when there is data from both coroutines and A>B. |
| ** |
| ** EofA: Called when data is exhausted from selectA. |
| ** |
| ** EofB: Called when data is exhausted from selectB. |
| ** |
| ** The implementation of the latter five subroutines depend on which |
| ** <operator> is used: |
| ** |
| ** |
| ** UNION ALL UNION EXCEPT INTERSECT |
| ** ------------- ----------------- -------------- ----------------- |
| ** AltB: outA, nextA outA, nextA outA, nextA nextA |
| ** |
| ** AeqB: outA, nextA nextA nextA outA, nextA |
| ** |
| ** AgtB: outB, nextB outB, nextB nextB nextB |
| ** |
| ** EofA: outB, nextB outB, nextB halt halt |
| ** |
| ** EofB: outA, nextA outA, nextA outA, nextA halt |
| ** |
| ** In the AltB, AeqB, and AgtB subroutines, an EOF on A following nextA |
| ** causes an immediate jump to EofA and an EOF on B following nextB causes |
| ** an immediate jump to EofB. Within EofA and EofB, and EOF on entry or |
| ** following nextX causes a jump to the end of the select processing. |
| ** |
| ** Duplicate removal in the UNION, EXCEPT, and INTERSECT cases is handled |
| ** within the output subroutine. The regPrev register set holds the previously |
| ** output value. A comparison is made against this value and the output |
| ** is skipped if the next results would be the same as the previous. |
| ** |
| ** The implementation plan is to implement the two coroutines and seven |
| ** subroutines first, then put the control logic at the bottom. Like this: |
| ** |
| ** goto Init |
| ** coA: coroutine for left query (A) |
| ** coB: coroutine for right query (B) |
| ** outA: output one row of A |
| ** outB: output one row of B (UNION and UNION ALL only) |
| ** EofA: ... |
| ** EofB: ... |
| ** AltB: ... |
| ** AeqB: ... |
| ** AgtB: ... |
| ** Init: initialize coroutine registers |
| ** yield coA |
| ** if eof(A) goto EofA |
| ** yield coB |
| ** if eof(B) goto EofB |
| ** Cmpr: Compare A, B |
| ** Jump AltB, AeqB, AgtB |
| ** End: ... |
| ** |
| ** We call AltB, AeqB, AgtB, EofA, and EofB "subroutines" but they are not |
| ** actually called using Gosub and they do not Return. EofA and EofB loop |
| ** until all data is exhausted then jump to the "end" labe. AltB, AeqB, |
| ** and AgtB jump to either L2 or to one of EofA or EofB. |
| */ |
| #ifndef SQLITE_OMIT_COMPOUND_SELECT |
| static int multiSelectOrderBy( |
| Parse *pParse, /* Parsing context */ |
| Select *p, /* The right-most of SELECTs to be coded */ |
| SelectDest *pDest /* What to do with query results */ |
| ){ |
| int i, j; /* Loop counters */ |
| Select *pPrior; /* Another SELECT immediately to our left */ |
| Vdbe *v; /* Generate code to this VDBE */ |
| SelectDest destA; /* Destination for coroutine A */ |
| SelectDest destB; /* Destination for coroutine B */ |
| int regAddrA; /* Address register for select-A coroutine */ |
| int regEofA; /* Flag to indicate when select-A is complete */ |
| int regAddrB; /* Address register for select-B coroutine */ |
| int regEofB; /* Flag to indicate when select-B is complete */ |
| int addrSelectA; /* Address of the select-A coroutine */ |
| int addrSelectB; /* Address of the select-B coroutine */ |
| int regOutA; /* Address register for the output-A subroutine */ |
| int regOutB; /* Address register for the output-B subroutine */ |
| int addrOutA; /* Address of the output-A subroutine */ |
| int addrOutB = 0; /* Address of the output-B subroutine */ |
| int addrEofA; /* Address of the select-A-exhausted subroutine */ |
| int addrEofB; /* Address of the select-B-exhausted subroutine */ |
| int addrAltB; /* Address of the A<B subroutine */ |
| int addrAeqB; /* Address of the A==B subroutine */ |
| int addrAgtB; /* Address of the A>B subroutine */ |
| int regLimitA; /* Limit register for select-A */ |
| int regLimitB; /* Limit register for select-A */ |
| int regPrev; /* A range of registers to hold previous output */ |
| int savedLimit; /* Saved value of p->iLimit */ |
| int savedOffset; /* Saved value of p->iOffset */ |
| int labelCmpr; /* Label for the start of the merge algorithm */ |
| int labelEnd; /* Label for the end of the overall SELECT stmt */ |
| int j1; /* Jump instructions that get retargetted */ |
| int op; /* One of TK_ALL, TK_UNION, TK_EXCEPT, TK_INTERSECT */ |
| KeyInfo *pKeyDup = 0; /* Comparison information for duplicate removal */ |
| KeyInfo *pKeyMerge; /* Comparison information for merging rows */ |
| sqlite3 *db; /* Database connection */ |
| ExprList *pOrderBy; /* The ORDER BY clause */ |
| int nOrderBy; /* Number of terms in the ORDER BY clause */ |
| int *aPermute; /* Mapping from ORDER BY terms to result set columns */ |
| #ifndef SQLITE_OMIT_EXPLAIN |
| int iSub1; /* EQP id of left-hand query */ |
| int iSub2; /* EQP id of right-hand query */ |
| #endif |
| |
| assert( p->pOrderBy!=0 ); |
| assert( pKeyDup==0 ); /* "Managed" code needs this. Ticket #3382. */ |
| db = pParse->db; |
| v = pParse->pVdbe; |
| assert( v!=0 ); /* Already thrown the error if VDBE alloc failed */ |
| labelEnd = sqlite3VdbeMakeLabel(v); |
| labelCmpr = sqlite3VdbeMakeLabel(v); |
| |
| |
| /* Patch up the ORDER BY clause |
| */ |
| op = p->op; |
| pPrior = p->pPrior; |
| assert( pPrior->pOrderBy==0 ); |
| pOrderBy = p->pOrderBy; |
| assert( pOrderBy ); |
| nOrderBy = pOrderBy->nExpr; |
| |
| /* For operators other than UNION ALL we have to make sure that |
| ** the ORDER BY clause covers every term of the result set. Add |
| ** terms to the ORDER BY clause as necessary. |
| */ |
| if( op!=TK_ALL ){ |
| for(i=1; db->mallocFailed==0 && i<=p->pEList->nExpr; i++){ |
| struct ExprList_item *pItem; |
| for(j=0, pItem=pOrderBy->a; j<nOrderBy; j++, pItem++){ |
| assert( pItem->iCol>0 ); |
| if( pItem->iCol==i ) break; |
| } |
| if( j==nOrderBy ){ |
| Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0); |
| if( pNew==0 ) return SQLITE_NOMEM; |
| pNew->flags |= EP_IntValue; |
| pNew->u.iValue = i; |
| pOrderBy = sqlite3ExprListAppend(pParse, pOrderBy, pNew); |
| pOrderBy->a[nOrderBy++].iCol = (u16)i; |
| } |
| } |
| } |
| |
| /* Compute the comparison permutation and keyinfo that is used with |
| ** the permutation used to determine if the next |
| ** row of results comes from selectA or selectB. Also add explicit |
| ** collations to the ORDER BY clause terms so that when the subqueries |
| ** to the right and the left are evaluated, they use the correct |
| ** collation. |
| */ |
| aPermute = sqlite3DbMallocRaw(db, sizeof(int)*nOrderBy); |
| if( aPermute ){ |
| struct ExprList_item *pItem; |
| for(i=0, pItem=pOrderBy->a; i<nOrderBy; i++, pItem++){ |
| assert( pItem->iCol>0 && pItem->iCol<=p->pEList->nExpr ); |
| aPermute[i] = pItem->iCol - 1; |
| } |
| pKeyMerge = |
| sqlite3DbMallocRaw(db, sizeof(*pKeyMerge)+nOrderBy*(sizeof(CollSeq*)+1)); |
| if( pKeyMerge ){ |
| pKeyMerge->aSortOrder = (u8*)&pKeyMerge->aColl[nOrderBy]; |
| pKeyMerge->nField = (u16)nOrderBy; |
| pKeyMerge->enc = ENC(db); |
| for(i=0; i<nOrderBy; i++){ |
| CollSeq *pColl; |
| Expr *pTerm = pOrderBy->a[i].pExpr; |
| if( pTerm->flags & EP_ExpCollate ){ |
| pColl = pTerm->pColl; |
| }else{ |
| pColl = multiSelectCollSeq(pParse, p, aPermute[i]); |
| pTerm->flags |= EP_ExpCollate; |
| pTerm->pColl = pColl; |
| } |
| pKeyMerge->aColl[i] = pColl; |
| pKeyMerge->aSortOrder[i] = pOrderBy->a[i].sortOrder; |
| } |
| } |
| }else{ |
| pKeyMerge = 0; |
| } |
| |
| /* Reattach the ORDER BY clause to the query. |
| */ |
| p->pOrderBy = pOrderBy; |
| pPrior->pOrderBy = sqlite3ExprListDup(pParse->db, pOrderBy, 0); |
| |
| /* Allocate a range of temporary registers and the KeyInfo needed |
| ** for the logic that removes duplicate result rows when the |
| ** operator is UNION, EXCEPT, or INTERSECT (but not UNION ALL). |
| */ |
| if( op==TK_ALL ){ |
| regPrev = 0; |
| }else{ |
| int nExpr = p->pEList->nExpr; |
| assert( nOrderBy>=nExpr || db->mallocFailed ); |
| regPrev = sqlite3GetTempRange(pParse, nExpr+1); |
| sqlite3VdbeAddOp2(v, OP_Integer, 0, regPrev); |
| pKeyDup = sqlite3DbMallocZero(db, |
| sizeof(*pKeyDup) + nExpr*(sizeof(CollSeq*)+1) ); |
| if( pKeyDup ){ |
| pKeyDup->aSortOrder = (u8*)&pKeyDup->aColl[nExpr]; |
| pKeyDup->nField = (u16)nExpr; |
| pKeyDup->enc = ENC(db); |
| for(i=0; i<nExpr; i++){ |
| pKeyDup->aColl[i] = multiSelectCollSeq(pParse, p, i); |
| pKeyDup->aSortOrder[i] = 0; |
| } |
| } |
| } |
| |
| /* Separate the left and the right query from one another |
| */ |
| p->pPrior = 0; |
| sqlite3ResolveOrderGroupBy(pParse, p, p->pOrderBy, "ORDER"); |
| if( pPrior->pPrior==0 ){ |
| sqlite3ResolveOrderGroupBy(pParse, pPrior, pPrior->pOrderBy, "ORDER"); |
| } |
| |
| /* Compute the limit registers */ |
| computeLimitRegisters(pParse, p, labelEnd); |
| if( p->iLimit && op==TK_ALL ){ |
| regLimitA = ++pParse->nMem; |
| regLimitB = ++pParse->nMem; |
| sqlite3VdbeAddOp2(v, OP_Copy, p->iOffset ? p->iOffset+1 : p->iLimit, |
| regLimitA); |
| sqlite3VdbeAddOp2(v, OP_Copy, regLimitA, regLimitB); |
| }else{ |
| regLimitA = regLimitB = 0; |
| } |
| sqlite3ExprDelete(db, p->pLimit); |
| p->pLimit = 0; |
| sqlite3ExprDelete(db, p->pOffset); |
| p->pOffset = 0; |
| |
| regAddrA = ++pParse->nMem; |
| regEofA = ++pParse->nMem; |
| regAddrB = ++pParse->nMem; |
| regEofB = ++pParse->nMem; |
| regOutA = ++pParse->nMem; |
| regOutB = ++pParse->nMem; |
| sqlite3SelectDestInit(&destA, SRT_Coroutine, regAddrA); |
| sqlite3SelectDestInit(&destB, SRT_Coroutine, regAddrB); |
| |
| /* Jump past the various subroutines and coroutines to the main |
| ** merge loop |
| */ |
| j1 = sqlite3VdbeAddOp0(v, OP_Goto); |
| addrSelectA = sqlite3VdbeCurrentAddr(v); |
| |
| |
| /* Generate a coroutine to evaluate the SELECT statement to the |
| ** left of the compound operator - the "A" select. |
| */ |
| VdbeNoopComment((v, "Begin coroutine for left SELECT")); |
| pPrior->iLimit = regLimitA; |
| explainSetInteger(iSub1, pParse->iNextSelectId); |
| sqlite3Select(pParse, pPrior, &destA); |
| sqlite3VdbeAddOp2(v, OP_Integer, 1, regEofA); |
| sqlite3VdbeAddOp1(v, OP_Yield, regAddrA); |
| VdbeNoopComment((v, "End coroutine for left SELECT")); |
| |
| /* Generate a coroutine to evaluate the SELECT statement on |
| ** the right - the "B" select |
| */ |
| addrSelectB = sqlite3VdbeCurrentAddr(v); |
| VdbeNoopComment((v, "Begin coroutine for right SELECT")); |
| savedLimit = p->iLimit; |
| savedOffset = p->iOffset; |
| p->iLimit = regLimitB; |
| p->iOffset = 0; |
| explainSetInteger(iSub2, pParse->iNextSelectId); |
| sqlite3Select(pParse, p, &destB); |
| p->iLimit = savedLimit; |
| p->iOffset = savedOffset; |
| sqlite3VdbeAddOp2(v, OP_Integer, 1, regEofB); |
| sqlite3VdbeAddOp1(v, OP_Yield, regAddrB); |
| VdbeNoopComment((v, "End coroutine for right SELECT")); |
| |
| /* Generate a subroutine that outputs the current row of the A |
| ** select as the next output row of the compound select. |
| */ |
| VdbeNoopComment((v, "Output routine for A")); |
| addrOutA = generateOutputSubroutine(pParse, |
| p, &destA, pDest, regOutA, |
| regPrev, pKeyDup, P4_KEYINFO_HANDOFF, labelEnd); |
| |
| /* Generate a subroutine that outputs the current row of the B |
| ** select as the next output row of the compound select. |
| */ |
| if( op==TK_ALL || op==TK_UNION ){ |
| VdbeNoopComment((v, "Output routine for B")); |
| addrOutB = generateOutputSubroutine(pParse, |
| p, &destB, pDest, regOutB, |
| regPrev, pKeyDup, P4_KEYINFO_STATIC, labelEnd); |
| } |
| |
| /* Generate a subroutine to run when the results from select A |
| ** are exhausted and only data in select B remains. |
| */ |
| VdbeNoopComment((v, "eof-A subroutine")); |
| if( op==TK_EXCEPT || op==TK_INTERSECT ){ |
| addrEofA = sqlite3VdbeAddOp2(v, OP_Goto, 0, labelEnd); |
| }else{ |
| addrEofA = sqlite3VdbeAddOp2(v, OP_If, regEofB, labelEnd); |
| sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB); |
| sqlite3VdbeAddOp1(v, OP_Yield, regAddrB); |
| sqlite3VdbeAddOp2(v, OP_Goto, 0, addrEofA); |
| p->nSelectRow += pPrior->nSelectRow; |
| } |
| |
| /* Generate a subroutine to run when the results from select B |
| ** are exhausted and only data in select A remains. |
| */ |
| if( op==TK_INTERSECT ){ |
| addrEofB = addrEofA; |
| if( p->nSelectRow > pPrior->nSelectRow ) p->nSelectRow = pPrior->nSelectRow; |
| }else{ |
| VdbeNoopComment((v, "eof-B subroutine")); |
| addrEofB = sqlite3VdbeAddOp2(v, OP_If, regEofA, labelEnd); |
| sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA); |
| sqlite3VdbeAddOp1(v, OP_Yield, regAddrA); |
| sqlite3VdbeAddOp2(v, OP_Goto, 0, addrEofB); |
| } |
| |
| /* Generate code to handle the case of A<B |
| */ |
| VdbeNoopComment((v, "A-lt-B subroutine")); |
| addrAltB = sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA); |
| sqlite3VdbeAddOp1(v, OP_Yield, regAddrA); |
| sqlite3VdbeAddOp2(v, OP_If, regEofA, addrEofA); |
| sqlite3VdbeAddOp2(v, OP_Goto, 0, labelCmpr); |
| |
| /* Generate code to handle the case of A==B |
| */ |
| if( op==TK_ALL ){ |
| addrAeqB = addrAltB; |
| }else if( op==TK_INTERSECT ){ |
| addrAeqB = addrAltB; |
| addrAltB++; |
| }else{ |
| VdbeNoopComment((v, "A-eq-B subroutine")); |
| addrAeqB = |
| sqlite3VdbeAddOp1(v, OP_Yield, regAddrA); |
| sqlite3VdbeAddOp2(v, OP_If, regEofA, addrEofA); |
| sqlite3VdbeAddOp2(v, OP_Goto, 0, labelCmpr); |
| } |
| |
| /* Generate code to handle the case of A>B |
| */ |
| VdbeNoopComment((v, "A-gt-B subroutine")); |
| addrAgtB = sqlite3VdbeCurrentAddr(v); |
| if( op==TK_ALL || op==TK_UNION ){ |
| sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB); |
| } |
| sqlite3VdbeAddOp1(v, OP_Yield, regAddrB); |
| sqlite3VdbeAddOp2(v, OP_If, regEofB, addrEofB); |
| sqlite3VdbeAddOp2(v, OP_Goto, 0, labelCmpr); |
| |
| /* This code runs once to initialize everything. |
| */ |
| sqlite3VdbeJumpHere(v, j1); |
| sqlite3VdbeAddOp2(v, OP_Integer, 0, regEofA); |
| sqlite3VdbeAddOp2(v, OP_Integer, 0, regEofB); |
| sqlite3VdbeAddOp2(v, OP_Gosub, regAddrA, addrSelectA); |
| sqlite3VdbeAddOp2(v, OP_Gosub, regAddrB, addrSelectB); |
| sqlite3VdbeAddOp2(v, OP_If, regEofA, addrEofA); |
| sqlite3VdbeAddOp2(v, OP_If, regEofB, addrEofB); |
| |
| /* Implement the main merge loop |
| */ |
| sqlite3VdbeResolveLabel(v, labelCmpr); |
| sqlite3VdbeAddOp4(v, OP_Permutation, 0, 0, 0, (char*)aPermute, P4_INTARRAY); |
| sqlite3VdbeAddOp4(v, OP_Compare, destA.iMem, destB.iMem, nOrderBy, |
| (char*)pKeyMerge, P4_KEYINFO_HANDOFF); |
| 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); |
| |
| /* Set the number of output columns |
| */ |
| if( pDest->eDest==SRT_Output ){ |
| Select *pFirst = pPrior; |
| while( pFirst->pPrior ) pFirst = pFirst->pPrior; |
| generateColumnNames(pParse, 0, pFirst->pEList); |
| } |
| |
| /* Reassembly the compound query so that it will be freed correctly |
| ** by the calling function */ |
| if( p->pPrior ){ |
| sqlite3SelectDelete(db, p->pPrior); |
| } |
| p->pPrior = pPrior; |
| |
| /*** TBD: Insert subroutine calls to close cursors on incomplete |
| **** subqueries ****/ |
| explainComposite(pParse, p->op, iSub1, iSub2, 0); |
| return SQLITE_OK; |
| } |
| #endif |
| |
| #if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) |
| /* Forward Declarations */ |
| static void substExprList(sqlite3*, ExprList*, int, ExprList*); |
| static void substSelect(sqlite3*, Select *, int, ExprList *); |
| |
| /* |
| ** Scan through the expression pExpr. Replace every reference to |
| ** a column in table number iTable with a copy of the iColumn-th |
| ** entry in pEList. (But leave references to the ROWID column |
| ** unchanged.) |
| ** |
| ** This routine is part of the flattening procedure. A subquery |
| ** whose result set is defined by pEList appears as entry in the |
| ** FROM clause of a SELECT such that the VDBE cursor assigned to that |
| ** FORM clause entry is iTable. This routine make the necessary |
| ** changes to pExpr so that it refers directly to the source table |
| ** of the subquery rather the result set of the subquery. |
| */ |
| static Expr *substExpr( |
| sqlite3 *db, /* Report malloc errors to this connection */ |
| Expr *pExpr, /* Expr in which substitution occurs */ |
| int iTable, /* Table to be substituted */ |
| ExprList *pEList /* Substitute expressions */ |
| ){ |
| if( pExpr==0 ) return 0; |
| if( pExpr->op==TK_COLUMN && pExpr->iTable==iTable ){ |
| if( pExpr->iColumn<0 ){ |
| pExpr->op = TK_NULL; |
| }else{ |
| Expr *pNew; |
| assert( pEList!=0 && pExpr->iColumn<pEList->nExpr ); |
| assert( pExpr->pLeft==0 && pExpr->pRight==0 ); |
| pNew = sqlite3ExprDup(db, pEList->a[pExpr->iColumn].pExpr, 0); |
| if( pNew && pExpr->pColl ){ |
| pNew->pColl = pExpr->pColl; |
| } |
| sqlite3ExprDelete(db, pExpr); |
| pExpr = pNew; |
| } |
| }else{ |
| pExpr->pLeft = substExpr(db, pExpr->pLeft, iTable, pEList); |
| pExpr->pRight = substExpr(db, pExpr->pRight, iTable, pEList); |
| if( ExprHasProperty(pExpr, EP_xIsSelect) ){ |
| substSelect(db, pExpr->x.pSelect, iTable, pEList); |
| }else{ |
| substExprList(db, pExpr->x.pList, iTable, pEList); |
| } |
| } |
| return pExpr; |
| } |
| static void substExprList( |
| sqlite3 *db, /* Report malloc errors here */ |
| ExprList *pList, /* List to scan and in which to make substitutes */ |
| int iTable, /* Table to be substituted */ |
| ExprList *pEList /* Substitute values */ |
| ){ |
| int i; |
| if( pList==0 ) return; |
| for(i=0; i<pList->nExpr; i++){ |
| pList->a[i].pExpr = substExpr(db, pList->a[i].pExpr, iTable, pEList); |
| } |
| } |
| static void substSelect( |
| sqlite3 *db, /* Report malloc errors here */ |
| Select *p, /* SELECT statement in which to make substitutions */ |
| 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); |
| substExprList(db, p->pOrderBy, iTable, pEList); |
| p->pHaving = substExpr(db, p->pHaving, iTable, pEList); |
| p->pWhere = substExpr(db, p->pWhere, iTable, pEList); |
| substSelect(db, p->pPrior, iTable, pEList); |
| pSrc = p->pSrc; |
| assert( pSrc ); /* Even for (SELECT 1) we have: pSrc!=0 but pSrc->nSrc==0 */ |
| if( ALWAYS(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) */ |
| |
| #if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) |
| /* |
| ** This routine attempts to flatten subqueries in order to speed |
| ** execution. It returns 1 if it makes changes and 0 if no flattening |
| ** occurs. |
| ** |
| ** To understand the concept of flattening, consider the following |
| ** query: |
| ** |
| ** SELECT a FROM (SELECT x+y AS a FROM t1 WHERE z<100) WHERE a>5 |
| ** |
| ** The default way of implementing this query is to execute the |
| ** subquery first and store the results in a temporary table, then |
| ** run the outer query on that temporary table. This requires two |
| ** passes over the data. Furthermore, because the temporary table |
| ** has no indices, the WHERE clause on the outer query cannot be |
| ** optimized. |
| ** |
| ** This routine attempts to rewrite queries such as the above into |
| ** a single flat select, like this: |
| ** |
| ** SELECT x+y AS a FROM t1 WHERE z<100 AND a>5 |
| ** |
| ** The code generated for this simpification gives the same result |
| ** but only has to scan the data once. And because indices might |
| ** exist on the table t1, a complete scan of the data might be |
| ** avoided. |
| ** |
| ** Flattening is only attempted if all of the following are true: |
| ** |
| ** (1) The subquery and the outer query do not both use aggregates. |
| ** |
| ** (2) The subquery is not an aggregate or the outer query is not a join. |
| ** |
| ** (3) The subquery is not the right operand of a left outer join |
| ** (Originally ticket #306. Strengthened by ticket #3300) |
| ** |
| ** (4) The subquery is not DISTINCT. |
| ** |
| ** (**) At one point restrictions (4) and (5) defined a subset of DISTINCT |
| ** sub-queries that were excluded from this optimization. Restriction |
| ** (4) has since been expanded to exclude all DISTINCT subqueries. |
| ** |
| ** (6) The subquery does not use aggregates or the outer query is not |
| ** DISTINCT. |
| ** |
| ** (7) The subquery has a FROM clause. |
| ** |
| ** (8) The subquery does not use LIMIT or the outer query is not a join. |
| ** |
| ** (9) The subquery does not use LIMIT or the outer query does not use |
| ** aggregates. |
| ** |
| ** (10) The subquery does not use aggregates or the outer query does not |
| ** use LIMIT. |
| ** |
| ** (11) The subquery and the outer query do not both have ORDER BY clauses. |
| ** |
| ** (**) Not implemented. Subsumed into restriction (3). Was previously |
| ** a separate restriction deriving from ticket #350. |
| ** |
| ** (13) The subquery and outer query do not both use LIMIT. |
| ** |
| ** (14) The subquery does not use OFFSET. |
| ** |
| ** (15) The outer query is not part of a compound select or the |
| ** subquery does not have a LIMIT clause. |
| ** (See ticket #2339 and ticket [02a8e81d44]). |
| ** |
| ** (16) The outer query is not an aggregate or the subquery does |
| ** not contain ORDER BY. (Ticket #2942) This used to not matter |
| ** until we introduced the group_concat() function. |
| ** |
| ** (17) The sub-query is not a compound select, or it is a UNION ALL |
| ** compound clause made up entirely of non-aggregate queries, and |
| ** the parent query: |
| ** |
| ** * is not itself part of a compound select, |
| ** * is not an aggregate or DISTINCT query, and |
| ** * has no other tables or sub-selects in the FROM clause. |
| ** |
| ** The parent and sub-query may contain WHERE clauses. Subject to |
| ** rules (11), (13) and (14), they may also contain ORDER BY, |
| ** LIMIT and OFFSET clauses. |
| ** |
| ** (18) If the sub-query is a compound select, then all terms of the |
| ** ORDER by clause of the parent must be simple references to |
| ** columns of the sub-query. |
| ** |
| ** (19) The subquery does not use LIMIT or the outer query does not |
| ** have a WHERE clause. |
| ** |
| ** (20) If the sub-query is a compound select, then it must not use |
| ** an ORDER BY clause. Ticket #3773. We could relax this constraint |
| ** somewhat by saying that the terms of the ORDER BY clause must |
| ** appear as unmodified result columns in the outer query. But |
| ** have other optimizations in mind to deal with that case. |
| ** |
| ** (21) The subquery does not use LIMIT or the outer query is not |
| ** DISTINCT. (See ticket [752e1646fc]). |
| ** |
| ** 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. |
| ** |
| ** If flattening is not attempted, this routine is a no-op and returns 0. |
| ** If flattening is attempted this routine returns 1. |
| ** |
| ** All of the expression analysis must occur on both the outer query and |
| ** the subquery before this routine runs. |
| */ |
| static int flattenSubquery( |
| Parse *pParse, /* Parsing context */ |
| Select *p, /* The parent or outer SELECT statement */ |
| int iFrom, /* Index in p->pSrc->a[] of the inner subquery */ |
| int isAgg, /* True if outer SELECT uses aggregate functions */ |
| int subqueryIsAgg /* True if the subquery uses aggregate functions */ |
| ){ |
| const char *zSavedAuthContext = pParse->zAuthContext; |
| Select *pParent; |
| Select *pSub; /* The inner query or "subquery" */ |
| Select *pSub1; /* Pointer to the rightmost select in sub-query */ |
| SrcList *pSrc; /* The FROM clause of the outer query */ |
| SrcList *pSubSrc; /* The FROM clause of the subquery */ |
| ExprList *pList; /* The result set of the outer query */ |
| int iParent; /* VDBE cursor number of the pSub result set temp table */ |
| int i; /* Loop counter */ |
| Expr *pWhere; /* The WHERE clause */ |
| struct SrcList_item *pSubitem; /* The subquery */ |
| sqlite3 *db = pParse->db; |
| |
| /* Check to see if flattening is permitted. Return 0 if not. |
| */ |
| assert( p!=0 ); |
| assert( p->pPrior==0 ); /* Unable to flatten compound queries */ |
| if( db->flags & SQLITE_QueryFlattener ) return 0; |
| pSrc = p->pSrc; |
| assert( pSrc && iFrom>=0 && iFrom<pSrc->nSrc ); |
| pSubitem = &pSrc->a[iFrom]; |
| iParent = pSubitem->iCursor; |
| pSub = pSubitem->pSelect; |
| assert( pSub!=0 ); |
| if( isAgg && subqueryIsAgg ) return 0; /* Restriction (1) */ |
| if( subqueryIsAgg && pSrc->nSrc>1 ) return 0; /* Restriction (2) */ |
| pSubSrc = pSub->pSrc; |
| assert( pSubSrc ); |
| /* Prior to version 3.1.2, when LIMIT and OFFSET had to be simple constants, |
| ** not arbitrary expresssions, we allowed some combining of LIMIT and OFFSET |
| ** because they could be computed at compile-time. But when LIMIT and OFFSET |
| ** became arbitrary expressions, we were forced to add restrictions (13) |
| ** and (14). */ |
| if( pSub->pLimit && p->pLimit ) return 0; /* Restriction (13) */ |
| if( pSub->pOffset ) return 0; /* Restriction (14) */ |
| if( p->pRightmost && pSub->pLimit ){ |
| return 0; /* Restriction (15) */ |
| } |
| if( pSubSrc->nSrc==0 ) return 0; /* Restriction (7) */ |
| if( pSub->selFlags & SF_Distinct ) return 0; /* Restriction (5) */ |
| if( pSub->pLimit && (pSrc->nSrc>1 || isAgg) ){ |
| return 0; /* Restrictions (8)(9) */ |
| } |
| if( (p->selFlags & SF_Distinct)!=0 && subqueryIsAgg ){ |
| return 0; /* Restriction (6) */ |
| } |
| if( p->pOrderBy && pSub->pOrderBy ){ |
| return 0; /* Restriction (11) */ |
| } |
| if( isAgg && pSub->pOrderBy ) return 0; /* Restriction (16) */ |
| if( pSub->pLimit && p->pWhere ) return 0; /* Restriction (19) */ |
| if( pSub->pLimit && (p->selFlags & SF_Distinct)!=0 ){ |
| return 0; /* Restriction (21) */ |
| } |
| |
| /* OBSOLETE COMMENT 1: |
| ** Restriction 3: If the subquery is a join, make sure the subquery is |
| ** not used as the right operand of an outer join. Examples of why this |
| ** is not allowed: |
| ** |
| ** t1 LEFT OUTER JOIN (t2 JOIN t3) |
| ** |
| ** If we flatten the above, we would get |
| ** |
| ** (t1 LEFT OUTER JOIN t2) JOIN t3 |
| ** |
| ** which is not at all the same thing. |
| ** |
| ** OBSOLETE COMMENT 2: |
| ** Restriction 12: If the subquery is the right operand of a left outer |
| ** join, make sure the subquery has no WHERE clause. |
| ** An examples of why this is not allowed: |
| ** |
| ** t1 LEFT OUTER JOIN (SELECT * FROM t2 WHERE t2.x>0) |
| ** |
| ** If we flatten the above, we would get |
| ** |
| ** (t1 LEFT OUTER JOIN t2) WHERE t2.x>0 |
| ** |
| ** But the t2.x>0 test will always fail on a NULL row of t2, which |
| ** effectively converts the OUTER JOIN into an INNER JOIN. |
| ** |
| ** THIS OVERRIDES OBSOLETE COMMENTS 1 AND 2 ABOVE: |
| ** Ticket #3300 shows that flattening the right term of a LEFT JOIN |
| ** is fraught with danger. Best to avoid the whole thing. If the |
| ** subquery is the right term of a LEFT JOIN, then do not flatten. |
| */ |
| if( (pSubitem->jointype & JT_OUTER)!=0 ){ |
| return 0; |
| } |
| |
| /* Restriction 17: If the sub-query is a compound SELECT, then it must |
| ** use only the UNION ALL operator. And none of the simple select queries |
| ** that make up the compound SELECT are allowed to be aggregate or distinct |
| ** queries. |
| */ |
| if( pSub->pPrior ){ |
| if( pSub->pOrderBy ){ |
| return 0; /* Restriction 20 */ |
| } |
| if( isAgg || (p->selFlags & SF_Distinct)!=0 || pSrc->nSrc!=1 ){ |
| return 0; |
| } |
| for(pSub1=pSub; pSub1; pSub1=pSub1->pPrior){ |
| testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct ); |
| testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate ); |
| if( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))!=0 |
| || (pSub1->pPrior && pSub1->op!=TK_ALL) |
| || NEVER(pSub1->pSrc==0) || pSub1->pSrc->nSrc!=1 |
| ){ |
| return 0; |
| } |
| } |
| |
| /* Restriction 18. */ |
| if( p->pOrderBy ){ |
| int ii; |
| for(ii=0; ii<p->pOrderBy->nExpr; ii++){ |
| if( p->pOrderBy->a[ii].iCol==0 ) return 0; |
| } |
| } |
| } |
| |
| /***** If we reach this point, flattening is permitted. *****/ |
| |
| /* Authorize the subquery */ |
| pParse->zAuthContext = pSubitem->zName; |
| sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0); |
| pParse->zAuthContext = zSavedAuthContext; |
| |
| /* If the sub-query is a compound SELECT statement, then (by restrictions |
| ** 17 and 18 above) it must be a UNION ALL and the parent query must |
| ** be of the form: |
| ** |
| ** SELECT <expr-list> FROM (<sub-query>) <where-clause> |
| ** |
| ** followed by any ORDER BY, LIMIT and/or OFFSET clauses. This block |
| ** creates N-1 copies of the parent query without any ORDER BY, LIMIT or |
| ** OFFSET clauses and joins them to the left-hand-side of the original |
| ** using UNION ALL operators. In this case N is the number of simple |
| ** select statements in the compound sub-query. |
| ** |
| ** Example: |
| ** |
| ** SELECT a+1 FROM ( |
| ** SELECT x FROM tab |
| ** UNION ALL |
| ** SELECT y FROM tab |
| ** UNION ALL |
| ** SELECT abs(z*2) FROM tab2 |
| ** ) WHERE a!=5 ORDER BY 1 |
| ** |
| ** Transformed into: |
| ** |
| ** SELECT x+1 FROM tab WHERE x+1!=5 |
| ** UNION ALL |
| ** SELECT y+1 FROM tab WHERE y+1!=5 |
| ** UNION ALL |
| ** SELECT abs(z*2)+1 FROM tab2 WHERE abs(z*2)+1!=5 |
| ** ORDER BY 1 |
| ** |
| ** We call this the "compound-subquery flattening". |
| */ |
| for(pSub=pSub->pPrior; pSub; pSub=pSub->pPrior){ |
| Select *pNew; |
| ExprList *pOrderBy = p->pOrderBy; |
| Expr *pLimit = p->pLimit; |
| Select *pPrior = p->pPrior; |
| p->pOrderBy = 0; |
| p->pSrc = 0; |
| p->pPrior = 0; |
| p->pLimit = 0; |
| pNew = sqlite3SelectDup(db, p, 0); |
| p->pLimit = pLimit; |
| p->pOrderBy = pOrderBy; |
| p->pSrc = pSrc; |
| p->op = TK_ALL; |
| p->pRightmost = 0; |
| if( pNew==0 ){ |
| pNew = pPrior; |
| }else{ |
| pNew->pPrior = pPrior; |
| pNew->pRightmost = 0; |
| } |
| p->pPrior = pNew; |
| if( db->mallocFailed ) return 1; |
| } |
| |
| /* Begin flattening the iFrom-th entry of the FROM clause |
| ** in the outer query. |
| */ |
| pSub = pSub1 = pSubitem->pSelect; |
| |
| /* Delete the transient table structure associated with the |
| ** subquery |
| */ |
| sqlite3DbFree(db, pSubitem->zDatabase); |
| sqlite3DbFree(db, pSubitem->zName); |
| sqlite3DbFree(db, pSubitem->zAlias); |
| pSubitem->zDatabase = 0; |
| pSubitem->zName = 0; |
| pSubitem->zAlias = 0; |
| pSubitem->pSelect = 0; |
| |
| /* Defer deleting the Table object associated with the |
| ** subquery until code generation is |
| ** complete, since there may still exist Expr.pTab entries that |
| ** refer to the subquery even after flattening. Ticket #3346. |
| ** |
| ** pSubitem->pTab is always non-NULL by test restrictions and tests above. |
| */ |
| if( ALWAYS(pSubitem->pTab!=0) ){ |
| Table *pTabToDel = pSubitem->pTab; |
| if( pTabToDel->nRef==1 ){ |
| Parse *pToplevel = sqlite3ParseToplevel(pParse); |
| pTabToDel->pNextZombie = pToplevel->pZombieTab; |
| pToplevel->pZombieTab = pTabToDel; |
| }else{ |
| pTabToDel->nRef--; |
| } |
| pSubitem->pTab = 0; |
| } |
| |
| /* The following loop runs once for each term in a compound-subquery |
| ** flattening (as described above). If we are doing a different kind |
| ** of flattening - a flattening other than a compound-subquery flattening - |
| ** then this loop only runs once. |
| ** |
| ** This loop moves all of the FROM elements of the subquery into the |
| ** the FROM clause of the outer query. Before doing this, remember |
| ** the cursor number for the original outer query FROM element in |
| ** iParent. The iParent cursor will never be used. Subsequent code |
| ** will scan expressions looking for iParent references and replace |
| ** those references with expressions that resolve to the subquery FROM |
| ** elements we are now copying in. |
| */ |
| for(pParent=p; pParent; pParent=pParent->pPrior, pSub=pSub->pPrior){ |
| int nSubSrc; |
| u8 jointype = 0; |
| pSubSrc = pSub->pSrc; /* FROM clause of subquery */ |
| nSubSrc = pSubSrc->nSrc; /* Number of terms in subquery FROM clause */ |
| pSrc = pParent->pSrc; /* FROM clause of the outer query */ |
| |
| if( pSrc ){ |
| assert( pParent==p ); /* First time through the loop */ |
| jointype = pSubitem->jointype; |
| }else{ |
| assert( pParent!=p ); /* 2nd and subsequent times through the loop */ |
| pSrc = pParent->pSrc = sqlite3SrcListAppend(db, 0, 0, 0); |
| if( pSrc==0 ){ |
| assert( db->mallocFailed ); |
| break; |
| } |
| } |
| |
| /* The subquery uses a single slot of the FROM clause of the outer |
| ** query. If the subquery has more than one element in its FROM clause, |
| ** then expand the outer query to make space for it to hold all elements |
| ** of the subquery. |
| ** |
| ** Example: |
| ** |
| ** SELECT * FROM tabA, (SELECT * FROM sub1, sub2), tabB; |
| ** |
| ** The outer query has 3 slots in its FROM clause. One slot of the |
| ** outer query (the middle slot) is used by the subquery. The next |
| ** block of code will expand the out query to 4 slots. The middle |
| ** slot is expanded to two slots in order to make space for the |
| ** two elements in the FROM clause of the subquery. |
| */ |
| if( nSubSrc>1 ){ |
| pParent->pSrc = pSrc = sqlite3SrcListEnlarge(db, pSrc, nSubSrc-1,iFrom+1); |
| if( db->mallocFailed ){ |
| break; |
| } |
| } |
| |
| /* Transfer the FROM clause terms from the subquery into the |
| ** outer query. |
| */ |
| for(i=0; i<nSubSrc; i++){ |
| sqlite3IdListDelete(db, pSrc->a[i+iFrom].pUsing); |
| pSrc->a[i+iFrom] = pSubSrc->a[i]; |
| memset(&pSubSrc->a[i], 0, sizeof(pSubSrc->a[i])); |
| } |
| pSrc->a[iFrom].jointype = jointype; |
| |
| /* Now begin substituting subquery result set expressions for |
| ** references to the iParent in the outer query. |
| ** |
| ** Example: |
| ** |
| ** SELECT a+5, b*10 FROM (SELECT x*3 AS a, y+10 AS b FROM t1) WHERE a>b; |
| ** \ \_____________ subquery __________/ / |
| ** \_____________________ outer query ______________________________/ |
| ** |
| ** We look at every expression in the outer query and every place we see |
| ** "a" we substitute "x*3" and every place we see "b" we substitute "y+10". |
| */ |
| pList = pParent->pEList; |
| for(i=0; i<pList->nExpr; i++){ |
| if( pList->a[i].zName==0 ){ |
| const char *zSpan = pList->a[i].zSpan; |
| if( ALWAYS(zSpan) ){ |
| pList->a[i].zName = sqlite3DbStrDup(db, zSpan); |
| } |
| } |
| } |
| substExprList(db, pParent->pEList, iParent, pSub->pEList); |
| if( isAgg ){ |
| substExprList(db, pParent->pGroupBy, iParent, pSub->pEList); |
| pParent->pHaving = substExpr(db, pParent->pHaving, iParent, pSub->pEList); |
| } |
| if( pSub->pOrderBy ){ |
| assert( pParent->pOrderBy==0 ); |
| pParent->pOrderBy = pSub->pOrderBy; |
| pSub->pOrderBy = 0; |
| }else if( pParent->pOrderBy ){ |
| substExprList(db, pParent->pOrderBy, iParent, pSub->pEList); |
| } |
| if( pSub->pWhere ){ |
| pWhere = sqlite3ExprDup(db, pSub->pWhere, 0); |
| }else{ |
| pWhere = 0; |
| } |
| if( subqueryIsAgg ){ |
| assert( pParent->pHaving==0 ); |
| pParent->pHaving = pParent->pWhere; |
| pParent->pWhere = pWhere; |
| pParent->pHaving = substExpr(db, pParent->pHaving, iParent, pSub->pEList); |
| pParent->pHaving = sqlite3ExprAnd(db, pParent->pHaving, |
| sqlite3ExprDup(db, pSub->pHaving, 0)); |
| assert( pParent->pGroupBy==0 ); |
| pParent->pGroupBy = sqlite3ExprListDup(db, pSub->pGroupBy, 0); |
| }else{ |
| pParent->pWhere = substExpr(db, pParent->pWhere, iParent, pSub->pEList); |
| pParent->pWhere = sqlite3ExprAnd(db, pParent->pWhere, pWhere); |
| } |
| |
| /* The flattened query is distinct if either the inner or the |
| ** outer query is distinct. |
| */ |
| pParent->selFlags |= pSub->selFlags & SF_Distinct; |
| |
| /* |
| ** SELECT ... FROM (SELECT ... LIMIT a OFFSET b) LIMIT x OFFSET y; |
| ** |
| ** One is tempted to try to add a and b to combine the limits. But this |
| ** does not work if either limit is negative. |
| */ |
| if( pSub->pLimit ){ |
| pParent->pLimit = pSub->pLimit; |
| pSub->pLimit = 0; |
| } |
| } |
| |
| /* Finially, delete what is left of the subquery and return |
| ** success. |
| */ |
| sqlite3SelectDelete(db, pSub1); |
| |
| return 1; |
| } |
| #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: |
| ** |
| ** 1. There is a single object in the FROM clause. |
| ** |
| ** 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. |
| */ |
| 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; |
| } |
| return WHERE_ORDERBY_NORMAL; |
| } |
| |
| /* |
| ** The select statement passed as the first argument is an aggregate query. |
| ** The second argment is the associated aggregate-info object. This |
| ** function tests if the SELECT is of the form: |
| ** |
| ** SELECT count(*) FROM <tbl> |
| ** |
| ** where table is a database table, not a sub-select or view. If the query |
| ** does match this pattern, then a pointer to the Table object representing |
| ** <tbl> is returned. Otherwise, 0 is returned. |
| */ |
| static Table *isSimpleCount(Select *p, AggInfo *pAggInfo){ |
| Table *pTab; |
| Expr *pExpr; |
| |
| assert( !p->pGroupBy ); |
| |
| if( p->pWhere || p->pEList->nExpr!=1 |
| || p->pSrc->nSrc!=1 || p->pSrc->a[0].pSelect |
| ){ |
| return 0; |
| } |
| pTab = p->pSrc->a[0].pTab; |
| pExpr = p->pEList->a[0].pExpr; |
| assert( pTab && !pTab->pSelect && pExpr ); |
| |
| if( IsVirtual(pTab) ) return 0; |
| if( pExpr->op!=TK_AGG_FUNCTION ) return 0; |
| if( (pAggInfo->aFunc[0].pFunc->flags&SQLITE_FUNC_COUNT)==0 ) return 0; |
| if( pExpr->flags&EP_Distinct ) return 0; |
| |
| return pTab; |
| } |
| |
| /* |
| ** If the source-list item passed as an argument was augmented with an |
| ** INDEXED BY clause, then try to locate the specified index. If there |
| ** was such a clause and the named index cannot be found, return |
| ** SQLITE_ERROR and leave an error in pParse. Otherwise, populate |
| ** pFrom->pIndex and return SQLITE_OK. |
| */ |
| int sqlite3IndexedByLookup(Parse *pParse, struct SrcList_item *pFrom){ |
| if( pFrom->pTab && pFrom->zIndex ){ |
| Table *pTab = pFrom->pTab; |
| char *zIndex = pFrom->zIndex; |
| Index *pIdx; |
| for(pIdx=pTab->pIndex; |
| pIdx && sqlite3StrICmp(pIdx->zName, zIndex); |
| pIdx=pIdx->pNext |
| ); |
| if( !pIdx ){ |
| sqlite3ErrorMsg(pParse, "no such index: %s", zIndex, 0); |
| pParse->checkSchema = 1; |
| return SQLITE_ERROR; |
| } |
| pFrom->pIndex = pIdx; |
| } |
| return SQLITE_OK; |
| } |
| |
| /* |
| ** This routine is a Walker callback for "expanding" a SELECT statement. |
| ** "Expanding" means to do the following: |
| ** |
| ** (1) Make sure VDBE cursor numbers have been assigned to every |
| ** element of the FROM clause. |
| ** |
| ** (2) Fill in the pTabList->a[].pTab fields in the SrcList that |
| ** defines FROM clause. When views appear in the FROM clause, |
| ** fill pTabList->a[].pSelect with a copy of the SELECT statement |
| ** that implements the view. A copy is made of the view's SELECT |
| ** statement so that we can freely modify or delete that statement |
| ** without worrying about messing up the presistent representation |
| ** of the view. |
| ** |
| ** (3) Add terms to the WHERE clause to accomodate the NATURAL keyword |
| ** on joins and the ON and USING clause of joins. |
| ** |
| ** (4) Scan the list of columns in the result set (pEList) looking |
| ** for instances of the "*" operator or the TABLE.* operator. |
| ** If found, expand each "*" to be every column in every table |
| ** and TABLE.* to be every column in TABLE. |
| ** |
| */ |
| static int selectExpander(Walker *pWalker, Select *p){ |
| Parse *pParse = pWalker->pParse; |
| int i, j, k; |
| SrcList *pTabList; |
| ExprList *pEList; |
| struct SrcList_item *pFrom; |
| sqlite3 *db = pParse->db; |
| |
| if( db->mallocFailed ){ |
| return WRC_Abort; |
| } |
| if( NEVER(p->pSrc==0) || (p->selFlags & SF_Expanded)!=0 ){ |
| return WRC_Prune; |
| } |
| p->selFlags |= SF_Expanded; |
| pTabList = p->pSrc; |
| pEList = p->pEList; |
| |
| /* Make sure cursor numbers have been assigned to all entries in |
| ** the FROM clause of the SELECT statement. |
| */ |
| sqlite3SrcListAssignCursors(pParse, pTabList); |
| |
| /* Look up every table named in the FROM clause of the select. If |
| ** an entry of the FROM clause is a subquery instead of a table or view, |
| ** then create a transient table structure to describe the subquery. |
| */ |
| for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){ |
| Table *pTab; |
| if( pFrom->pTab!=0 ){ |
| /* This statement has already been prepared. There is no need |
| ** to go further. */ |
| assert( i==0 ); |
| return WRC_Prune; |
| } |
| if( pFrom->zName==0 ){ |
| #ifndef SQLITE_OMIT_SUBQUERY |
| Select *pSel = pFrom->pSelect; |
| /* A sub-query in the FROM clause of a SELECT */ |
| assert( pSel!=0 ); |
| assert( pFrom->pTab==0 ); |
| sqlite3WalkSelect(pWalker, pSel); |
| pFrom->pTab = pTab = sqlite3DbMallocZero(db, sizeof(Table)); |
| if( pTab==0 ) return WRC_Abort; |
| pTab->nRef = 1; |
| pTab->zName = sqlite3MPrintf(db, "sqlite_subquery_%p_", (void*)pTab); |
| while( pSel->pPrior ){ pSel = pSel->pPrior; } |
| selectColumnsFromExprList(pParse, pSel->pEList, &pTab->nCol, &pTab->aCol); |
| pTab->iPKey = -1; |
| pTab->nRowEst = 1000000; |
| pTab->tabFlags |= TF_Ephemeral; |
| #endif |
| }else{ |
| /* An ordinary table or view name in the FROM clause */ |
| assert( pFrom->pTab==0 ); |
| pFrom->pTab = pTab = |
| sqlite3LocateTable(pParse,0,pFrom->zName,pFrom->zDatabase); |
| if( pTab==0 ) return WRC_Abort; |
| pTab->nRef++; |
| #if !defined(SQLITE_OMIT_VIEW) || !defined (SQLITE_OMIT_VIRTUALTABLE) |
| if( pTab->pSelect || IsVirtual(pTab) ){ |
| /* We reach here if the named table is a really a view */ |
| if( sqlite3ViewGetColumnNames(pParse, pTab) ) return WRC_Abort; |
| assert( pFrom->pSelect==0 ); |
| pFrom->pSelect = sqlite3SelectDup(db, pTab->pSelect, 0); |
| sqlite3WalkSelect(pWalker, pFrom->pSelect); |
| } |
| #endif |
| } |
| |
| /* Locate the index named by the INDEXED BY clause, if any. */ |
| if( sqlite3IndexedByLookup(pParse, pFrom) ){ |
| return WRC_Abort; |
| } |
| } |
| |
| /* Process NATURAL keywords, and ON and USING clauses of joins. |
| */ |
| if( db->mallocFailed || sqliteProcessJoin(pParse, p) ){ |
| return WRC_Abort; |
| } |
| |
| /* For every "*" that occurs in the column list, insert the names of |
| ** all columns in all tables. And for every TABLE.* insert the names |
| ** of all columns in TABLE. The parser inserted a special expression |
| ** with the TK_ALL operator for each "*" that it found in the column list. |
| ** The following code just has to locate the TK_ALL expressions and expand |
| ** each one to the list of all columns in all tables. |
| ** |
| ** The first loop just checks to see if there are any "*" operators |
| ** that need expanding. |
| */ |
| for(k=0; k<pEList->nExpr; k++){ |
| Expr *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) ); |
| if( pE->op==TK_DOT && pE->pRight->op==TK_ALL ) break; |
| } |
| if( k<pEList->nExpr ){ |
| /* |
| ** If we get here it means the result set contains one or more "*" |
| ** operators that need to be expanded. Loop through each expression |
| ** in the result set and expand them one by one. |
| */ |
| struct ExprList_item *a = pEList->a; |
| ExprList *pNew = 0; |
| int flags = pParse->db->flags; |
| int longNames = (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) ){ |
| /* This particular expression does not need to be expanded. |
| */ |
| pNew = sqlite3ExprListAppend(pParse, pNew, a[k].pExpr); |
| if( pNew ){ |
| pNew->a[pNew->nExpr-1].zName = a[k].zName; |
| pNew->a[pNew->nExpr-1].zSpan = a[k].zSpan; |
| a[k].zName = 0; |
| a[k].zSpan = 0; |
| } |
| a[k].pExpr = 0; |
| }else{ |
| /* 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 */ |
| 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; |
| char *zTabName = pFrom->zAlias; |
| if( zTabName==0 ){ |
| zTabName = pTab->zName; |
| } |
| if( db->mallocFailed ) break; |
| if( zTName && sqlite3StrICmp(zTName, zTabName)!=0 ){ |
| continue; |
| } |
| 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 */ |
| |
| /* If a column is marked as 'hidden' (currently only possible |
| ** for virtual tables), do not include it in the expanded |
| ** result-set list. |
| */ |
| if( IsHiddenColumn(&pTab->aCol[j]) ){ |
| assert(IsVirtual(pTab)); |
| continue; |
| } |
| |
| if( i>0 && zTName==0 ){ |
| if( (pFrom->jointype & JT_NATURAL)!=0 |
| && tableAndColumnIndex(pTabList, i, zName, 0, 0) |
| ){ |
| /* In a NATURAL join, omit the join columns from the |
| ** table to the right of the join */ |
| continue; |
| } |
| if( sqlite3IdListIndex(pFrom->pUsing, zName)>=0 ){ |
| /* In a join with a USING clause, omit columns in the |
| ** using clause from the table on the right. */ |
| continue; |
| } |
| } |
| pRight = sqlite3Expr(db, TK_ID, zName); |
| zColname = zName; |
| zToFree = 0; |
| if( longNames || pTabList->nSrc>1 ){ |
| Expr *pLeft; |
| pLeft = sqlite3Expr(db, TK_ID, zTabName); |
| pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight, 0); |
| if( longNames ){ |
| zColname = sqlite3MPrintf(db, "%s.%s", zTabName, zName); |
| zToFree = zColname; |
| } |
| }else{ |
| pExpr = pRight; |
| } |
| pNew = sqlite3ExprListAppend(pParse, pNew, pExpr); |
| sColname.z = zColname; |
| sColname.n = sqlite3Strlen30(zColname); |
| sqlite3ExprListSetName(pParse, pNew, &sColname, 0); |
| sqlite3DbFree(db, zToFree); |
| } |
| } |
| if( !tableSeen ){ |
| if( zTName ){ |
| sqlite3ErrorMsg(pParse, "no such table: %s", zTName); |
| }else{ |
| sqlite3ErrorMsg(pParse, "no tables specified"); |
| } |
| } |
| } |
| } |
| sqlite3ExprListDelete(db, pEList); |
| p->pEList = pNew; |
| } |
| #if SQLITE_MAX_COLUMN |
| if( p->pEList && p->pEList->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){ |
| sqlite3ErrorMsg(pParse, "too many columns in result set"); |
| } |
| #endif |
| return WRC_Continue; |
| } |
| |
| /* |
| ** No-op routine for the parse-tree walker. |
| ** |
| ** When this routine is the Walker.xExprCallback then expression trees |
| ** are walked without any actions being taken at each node. Presumably, |
| ** when this routine is used for Walker.xExprCallback then |
| ** Walker.xSelectCallback is set to do something useful for every |
| ** subquery in the parser tree. |
| */ |
| static int exprWalkNoop(Walker *NotUsed, Expr *NotUsed2){ |
| UNUSED_PARAMETER2(NotUsed, NotUsed2); |
| return WRC_Continue; |
| } |
| |
| /* |
| ** This routine "expands" a SELECT statement and all of its subqueries. |
| ** For additional information on what it means to "expand" a SELECT |
| ** statement, see the comment on the selectExpand worker callback above. |
| ** |
| ** Expanding a SELECT statement is the first step in processing a |
| ** SELECT statement. The SELECT statement must be expanded before |
| ** name resolution is performed. |
| ** |
| ** If anything goes wrong, an error message is written into pParse. |
| ** The calling function can detect the problem by looking at pParse->nErr |
| ** and/or pParse->db->mallocFailed. |
| */ |
| static void sqlite3SelectExpand(Parse *pParse, Select *pSelect){ |
| Walker w; |
| w.xSelectCallback = selectExpander; |
| w.xExprCallback = exprWalkNoop; |
| w.pParse = pParse; |
| sqlite3WalkSelect(&w, pSelect); |
| } |
| |
| |
| #ifndef SQLITE_OMIT_SUBQUERY |
| /* |
| ** This is a Walker.xSelectCallback callback for the sqlite3SelectTypeInfo() |
| ** interface. |
| ** |
| ** For each FROM-clause subquery, add Column.zType and Column.zColl |
| ** information to the Table structure that represents the result set |
| ** of that subquery. |
| ** |
| ** The Table structure that represents the result set was constructed |
| ** by selectExpander() but the type and collation information was omitted |
| ** at that point because identifiers had not yet been resolved. This |
| ** routine is called after identifier resolution. |
| */ |
| static int selectAddSubqueryTypeInfo(Walker *pWalker, Select *p){ |
| Parse *pParse; |
| int i; |
| SrcList *pTabList; |
| struct SrcList_item *pFrom; |
| |
| assert( p->selFlags & SF_Resolved ); |
| if( (p->selFlags & SF_HasTypeInfo)==0 ){ |
| p->selFlags |= SF_HasTypeInfo; |
| pParse = pWalker->pParse; |
| pTabList = p->pSrc; |
| for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){ |
| Table *pTab = pFrom->pTab; |
| if( ALWAYS(pTab!=0) && (pTab->tabFlags & TF_Ephemeral)!=0 ){ |
| /* A sub-query in the FROM clause of a SELECT */ |
| Select *pSel = pFrom->pSelect; |
| assert( pSel ); |
| while( pSel->pPrior ) pSel = pSel->pPrior; |
| selectAddColumnTypeAndCollation(pParse, pTab->nCol, pTab->aCol, pSel); |
| } |
| } |
| } |
| return WRC_Continue; |
| } |
| #endif |
| |
| |
| /* |
| ** This routine adds datatype and collating sequence information to |
| ** the Table structures of all FROM-clause subqueries in a |
| ** SELECT statement. |
| ** |
| ** Use this routine after name resolution. |
| */ |
| static void sqlite3SelectAddTypeInfo(Parse *pParse, Select *pSelect){ |
| #ifndef SQLITE_OMIT_SUBQUERY |
| Walker w; |
| w.xSelectCallback = selectAddSubqueryTypeInfo; |
| w.xExprCallback = exprWalkNoop; |
| w.pParse = pParse; |
| sqlite3WalkSelect(&w, pSelect); |
| #endif |
| } |
| |
| |
| /* |
| ** This routine sets of a SELECT statement for processing. The |
| ** following is accomplished: |
| ** |
| ** * VDBE Cursor numbers are assigned to all FROM-clause terms. |
| ** * Ephemeral Table objects are created for all FROM-clause subqueries. |
| ** * ON and USING clauses are shifted into WHERE statements |
| ** * Wildcards "*" and "TABLE.*" in result sets are expanded. |
| ** * Identifiers in expression are matched to tables. |
| ** |
| ** This routine acts recursively on all subqueries within the SELECT. |
| */ |
| void sqlite3SelectPrep( |
| Parse *pParse, /* The parser context */ |
| Select *p, /* The SELECT statement being coded. */ |
| NameContext *pOuterNC /* Name context for container */ |
| ){ |
| sqlite3 *db; |
| if( NEVER(p==0) ) return; |
| db = pParse->db; |
| if( p->selFlags & SF_HasTypeInfo ) return; |
| sqlite3SelectExpand(pParse, p); |
| if( pParse->nErr || db->mallocFailed ) return; |
| sqlite3ResolveSelectNames(pParse, p, pOuterNC); |
| if( pParse->nErr || db->mallocFailed ) return; |
| sqlite3SelectAddTypeInfo(pParse, p); |
| } |
| |
| /* |
| ** Reset the aggregate accumulator. |
| ** |
| ** The aggregate accumulator is a set of memory cells that hold |
| ** intermediate results while calculating an aggregate. This |
| ** routine simply stores NULLs in all of those memory cells. |
| */ |
| static void resetAccumulator(Parse *pParse, AggInfo *pAggInfo){ |
| Vdbe *v = pParse->pVdbe; |
| int i; |
| struct AggInfo_func *pFunc; |
| if( pAggInfo->nFunc+pAggInfo->nColumn==0 ){ |
| return; |
| } |
| for(i=0; i<pAggInfo->nColumn; i++){ |
| sqlite3VdbeAddOp2(v, OP_Null, 0, pAggInfo->aCol[i].iMem); |
| } |
| for(pFunc=pAggInfo->aFunc, i=0; i<pAggInfo->nFunc; i++, pFunc++){ |
| sqlite3VdbeAddOp2(v, OP_Null, 0, pFunc->iMem); |
| if( pFunc->iDistinct>=0 ){ |
| Expr *pE = pFunc->pExpr; |
| assert( !ExprHasProperty(pE, EP_xIsSelect) ); |
| if( pE->x.pList==0 || pE->x.pList->nExpr!=1 ){ |
| sqlite3ErrorMsg(pParse, "DISTINCT aggregates must have exactly one " |
| "argument"); |
| pFunc->iDistinct = -1; |
| }else{ |
| KeyInfo *pKeyInfo = keyInfoFromExprList(pParse, pE->x.pList); |
| sqlite3VdbeAddOp4(v, OP_OpenEphemeral, pFunc->iDistinct, 0, 0, |
| (char*)pKeyInfo, P4_KEYINFO_HANDOFF); |
| } |
| } |
| } |
| } |
| |
| /* |
| ** Invoke the OP_AggFinalize opcode for every aggregate function |
| ** in the AggInfo structure. |
| */ |
| static void finalizeAggFunctions(Parse *pParse, AggInfo *pAggInfo){ |
| Vdbe *v = pParse->pVdbe; |
| int i; |
| struct AggInfo_func *pF; |
| for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){ |
| ExprList *pList = pF->pExpr->x.pList; |
| assert( !ExprHasProperty(pF->pExpr, EP_xIsSelect) ); |
| sqlite3VdbeAddOp4(v, OP_AggFinal, pF->iMem, pList ? pList->nExpr : 0, 0, |
| (void*)pF->pFunc, P4_FUNCDEF); |
| } |
| } |
| |
| /* |
| ** Update the accumulator memory cells for an aggregate based on |
| ** the current cursor position. |
| */ |
| static void updateAccumulator(Parse *pParse, AggInfo *pAggInfo){ |
| Vdbe *v = pParse->pVdbe; |
| int i; |
| struct AggInfo_func *pF; |
| struct AggInfo_col *pC; |
| |
| pAggInfo->directMode = 1; |
| sqlite3ExprCacheClear(pParse); |
| for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){ |
| int nArg; |
| int addrNext = 0; |
| int regAgg; |
| ExprList *pList = pF->pExpr->x.pList; |
| assert( !ExprHasProperty(pF->pExpr, EP_xIsSelect) ); |
| if( pList ){ |
| nArg = pList->nExpr; |
| regAgg = sqlite3GetTempRange(pParse, nArg); |
| sqlite3ExprCodeExprList(pParse, pList, regAgg, 1); |
| }else{ |
| nArg = 0; |
| regAgg = 0; |
| } |
| if( pF->iDistinct>=0 ){ |
| addrNext = sqlite3VdbeMakeLabel(v); |
| assert( nArg==1 ); |
| codeDistinct(pParse, pF->iDistinct, addrNext, 1, regAgg); |
| } |
| if( pF->pFunc->flags & SQLITE_FUNC_NEEDCOLL ){ |
| CollSeq *pColl = 0; |
| struct ExprList_item *pItem; |
| int j; |
| assert( pList!=0 ); /* pList!=0 if pF->pFunc has NEEDCOLL */ |
| for(j=0, pItem=pList->a; !pColl && j<nArg; j++, pItem++){ |
| pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr); |
| } |
| if( !pColl ){ |
| pColl = pParse->db->pDfltColl; |
| } |
| sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ); |
| } |
| sqlite3VdbeAddOp4(v, OP_AggStep, 0, regAgg, pF->iMem, |
| (void*)pF->pFunc, P4_FUNCDEF); |
| sqlite3VdbeChangeP5(v, (u8)nArg); |
| sqlite3ExprCacheAffinityChange(pParse, regAgg, nArg); |
| sqlite3ReleaseTempRange(pParse, regAgg, nArg); |
| if( addrNext ){ |
| sqlite3VdbeResolveLabel(v, addrNext); |
| sqlite3ExprCacheClear(pParse); |
| } |
| } |
| |
| /* Before populating the accumulator registers, clear the column cache. |
| ** Otherwise, if any of the required column values are already present |
| ** in registers, sqlite3ExprCode() may use OP_SCopy to copy the value |
| ** to pC->iMem. But by the time the value is used, the original register |
| ** may have been used, invalidating the underlying buffer holding the |
| ** text or blob value. See ticket [883034dcb5]. |
| ** |
| ** Another solution would be to change the OP_SCopy used to copy cached |
| ** values to an OP_Copy. |
| */ |
| sqlite3ExprCacheClear(pParse); |
| for(i=0, pC=pAggInfo->aCol; i<pAggInfo->nAccumulator; i++, pC++){ |
| sqlite3ExprCode(pParse, pC->pExpr, pC->iMem); |
| } |
| pAggInfo->directMode = 0; |
| sqlite3ExprCacheClear(pParse); |
| } |
| |
| /* |
| ** Add a single OP_Explain instruction to the VDBE to explain a simple |
| ** count(*) query ("SELECT count(*) FROM pTab"). |
| */ |
| #ifndef SQLITE_OMIT_EXPLAIN |
| static void explainSimpleCount( |
| Parse *pParse, /* Parse context */ |
| Table *pTab, /* Table being queried */ |
| Index *pIdx /* Index used to optimize scan, or NULL */ |
| ){ |
| if( pParse->explain==2 ){ |
| char *zEqp = sqlite3MPrintf(pParse->db, "SCAN TABLE %s %s%s(~%d rows)", |
| pTab->zName, |
| pIdx ? "USING COVERING INDEX " : "", |
| pIdx ? pIdx->zName : "", |
| pTab->nRowEst |
| ); |
| sqlite3VdbeAddOp4( |
| pParse->pVdbe, OP_Explain, pParse->iSelectId, 0, 0, zEqp, P4_DYNAMIC |
| ); |
| } |
| } |
| #else |
| # define explainSimpleCount(a,b,c) |
| #endif |
| |
| /* |
| ** Generate code for the SELECT statement given in the p argument. |
| ** |
| ** The results are distributed in various ways depending on the |
| ** contents of the SelectDest structure pointed to by argument pDest |
| ** as follows: |
| ** |
| ** pDest->eDest Result |
| ** ------------ ------------------------------------------- |
| ** SRT_Output Generate a row of output (using the OP_ResultRow |
| ** opcode) for each row in the result set. |
| ** |
| ** SRT_Mem Only valid if the result is a single column. |
| ** Store the first column of the first result row |
| ** in register pDest->iParm then abandon the rest |
| ** of the query. This destination implies "LIMIT 1". |
| ** |
| ** SRT_Set The result must be a single column. Store each |
| ** row of result as the key in table pDest->iParm. |
| ** Apply the affinity pDest->affinity before storing |
| ** results. Used to implement "IN (SELECT ...)". |
| ** |
| ** SRT_Union Store results as a key in a temporary table pDest->iParm. |
| ** |
| ** SRT_Except Remove results from the temporary table pDest->iParm. |
| ** |
| ** SRT_Table Store results in temporary table pDest->iParm. |
| ** This is like SRT_EphemTab except that the table |
| ** is assumed to already be open. |
| ** |
| ** SRT_EphemTab Create an temporary table pDest->iParm and store |
| ** the result there. The cursor is left open after |
| ** returning. This is like SRT_Table except that |
| ** this destination uses OP_OpenEphemeral to create |
| ** the table first. |
| ** |
| ** SRT_Coroutine Generate a co-routine that returns a new row of |
| ** results each time it is invoked. The entry point |
| ** of the co-routine is stored in register pDest->iParm. |
| ** |
| ** SRT_Exists Store a 1 in memory cell pDest->iParm if the result |
| ** set is not empty. |
| ** |
| ** SRT_Discard Throw the results away. This is used by SELECT |
| ** statements within triggers whose only purpose is |
| ** the side-effects of functions. |
| ** |
| ** This routine returns the number of errors. If any errors are |
| ** encountered, then an appropriate error message is left in |
| ** pParse->zErrMsg. |
| ** |
| ** This routine does NOT free the Select structure passed in. The |
| ** calling function needs to do that. |
| */ |
| int sqlite3Select( |
| Parse *pParse, /* The parser context */ |
| Select *p, /* The SELECT statement being coded. */ |
| SelectDest *pDest /* What to do with the query results */ |
| ){ |
| int i, j; /* Loop counters */ |
| WhereInfo *pWInfo; /* Return from sqlite3WhereBegin() */ |
| Vdbe *v; /* The virtual machine under construction */ |
| int isAgg; /* True for select lists like "count(*)" */ |
| ExprList *pEList; /* List of columns to extract. */ |
| SrcList *pTabList; /* List of tables to select from */ |
| Expr *pWhere; /* The WHERE clause. May be NULL */ |
| ExprList *pOrderBy; /* The ORDER BY clause. May be NULL */ |
| ExprList *pGroupBy; /* The GROUP BY clause. May be NULL */ |
| Expr *pHaving; /* The HAVING clause. May be NULL */ |
| int isDistinct; /* True if the DISTINCT keyword is present */ |
| int distinct; /* Table to use for the distinct set */ |
| int rc = 1; /* Value to return from this function */ |
| int addrSortIndex; /* Address of an OP_OpenEphemeral instruction */ |
| AggInfo sAggInfo; /* Information used by aggregate queries */ |
| int iEnd; /* Address of the end of the query */ |
| sqlite3 *db; /* The database connection */ |
| |
| #ifndef SQLITE_OMIT_EXPLAIN |
| int iRestoreSelectId = pParse->iSelectId; |
| pParse->iSelectId = pParse->iNextSelectId++; |
| #endif |
| |
| db = pParse->db; |
| if( p==0 || db->mallocFailed || pParse->nErr ){ |
| return 1; |
| } |
| if( sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0) ) return 1; |
| memset(&sAggInfo, 0, sizeof(sAggInfo)); |
| |
| if( IgnorableOrderby(pDest) ){ |
| assert(pDest->eDest==SRT_Exists || pDest->eDest==SRT_Union || |
| pDest->eDest==SRT_Except || pDest->eDest==SRT_Discard); |
| /* If ORDER BY makes no difference in the output then neither does |
| ** DISTINCT so it can be removed too. */ |
| sqlite3ExprListDelete(db, p->pOrderBy); |
| p->pOrderBy = 0; |
| p->selFlags &= ~SF_Distinct; |
| } |
| sqlite3SelectPrep(pParse, p, 0); |
| pOrderBy = p->pOrderBy; |
| pTabList = p->pSrc; |
| pEList = p->pEList; |
| if( pParse->nErr || db->mallocFailed ){ |
| goto select_end; |
| } |
| isAgg = (p->selFlags & SF_Aggregate)!=0; |
| assert( pEList!=0 ); |
| |
| /* Begin generating code. |
| */ |
| v = sqlite3GetVdbe(pParse); |
| if( v==0 ) goto select_end; |
| |
| /* If writing to memory or generating a set |
| ** only a single column may be output. |
| */ |
| #ifndef SQLITE_OMIT_SUBQUERY |
| if( checkForMultiColumnSelectError(pParse, pDest, pEList->nExpr) ){ |
| goto select_end; |
| } |
| #endif |
| |
| /* Generate code for all sub-queries in the FROM clause |
| */ |
| #if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) |
| for(i=0; !p->pPrior && i<pTabList->nSrc; i++){ |
| struct SrcList_item *pItem = &pTabList->a[i]; |
| SelectDest dest; |
| Select *pSub = pItem->pSelect; |
| int isAggSub; |
| |
| if( pSub==0 || pItem->isPopulated ) continue; |
| |
| /* Increment Parse.nHeight by the height of the largest expression |
| ** tree refered to by this, the parent select. The child select |
| ** may contain expression trees of at most |
| ** (SQLITE_MAX_EXPR_DEPTH-Parse.nHeight) height. This is a bit |
| ** more conservative than necessary, but much easier than enforcing |
| ** an exact limit. |
| */ |
| pParse->nHeight += sqlite3SelectExprHeight(p); |
| |
| /* Check to see if the subquery can be absorbed into the parent. */ |
| isAggSub = (pSub->selFlags & SF_Aggregate)!=0; |
| if( flattenSubquery(pParse, p, i, isAgg, isAggSub) ){ |
| if( isAggSub ){ |
| isAgg = 1; |
| p->selFlags |= SF_Aggregate; |
| } |
| i = -1; |
| }else{ |
| sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor); |
| assert( pItem->isPopulated==0 ); |
| explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId); |
| sqlite3Select(pParse, pSub, &dest); |
| pItem->isPopulated = 1; |
| pItem->pTab->nRowEst = (unsigned)pSub->nSelectRow; |
| } |
| if( /*pParse->nErr ||*/ db->mallocFailed ){ |
| goto select_end; |
| } |
| pParse->nHeight -= sqlite3SelectExprHeight(p); |
| pTabList = p->pSrc; |
| if( !IgnorableOrderby(pDest) ){ |
| pOrderBy = p->pOrderBy; |
| } |
| } |
| pEList = p->pEList; |
| #endif |
| pWhere = p->pWhere; |
| pGroupBy = p->pGroupBy; |
| pHaving = p->pHaving; |
| isDistinct = (p->selFlags & SF_Distinct)!=0; |
| |
| #ifndef SQLITE_OMIT_COMPOUND_SELECT |
| /* 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; |
| } |
| #endif |
| |
| /* If possible, rewrite the query to use GROUP BY instead of DISTINCT. |
| ** GROUP BY might use an index, DISTINCT never does. |
| */ |
| assert( p->pGroupBy==0 || (p->selFlags & SF_Aggregate)!=0 ); |
| if( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct ){ |
| p->pGroupBy = sqlite3ExprListDup(db, p->pEList, 0); |
| pGroupBy = p->pGroupBy; |
| p->selFlags &= ~SF_Distinct; |
| } |
| |
| /* If there is both a GROUP BY and an ORDER BY clause and they are |
| ** identical, then disable the ORDER BY clause since the GROUP BY |
| ** will cause elements to come out in the correct order. This is |
| ** an optimization - the correct answer should result regardless. |
| ** Use the SQLITE_GroupByOrder flag with SQLITE_TESTCTRL_OPTIMIZER |
| ** to disable this optimization for testing purposes. |
| */ |
| if( sqlite3ExprListCompare(p->pGroupBy, pOrderBy)==0 |
| && (db->flags & SQLITE_GroupByOrder)==0 ){ |
| pOrderBy = 0; |
| } |
| |
| /* If there is an ORDER BY clause, then this sorting |
| ** index might end up being unused if the data can be |
| ** extracted in pre-sorted order. If that is the case, then the |
| ** OP_OpenEphemeral instruction will be changed to an OP_Noop once |
| ** we figure out that the sorting index is not needed. The addrSortIndex |
| ** variable is used to facilitate that change. |
| */ |
| if( pOrderBy ){ |
| KeyInfo *pKeyInfo; |
| pKeyInfo = keyInfoFromExprList(pParse, pOrderBy); |
| pOrderBy->iECursor = pParse->nTab++; |
| p->addrOpenEphm[2] = addrSortIndex = |
| sqlite3VdbeAddOp4(v, OP_OpenEphemeral, |
| pOrderBy->iECursor, pOrderBy->nExpr+2, 0, |
| (char*)pKeyInfo, P4_KEYINFO_HANDOFF); |
| }else{ |
| addrSortIndex = -1; |
| } |
| |
| /* If the output is destined for a temporary table, open that table. |
| */ |
| if( pDest->eDest==SRT_EphemTab ){ |
| sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pDest->iParm, pEList->nExpr); |
| } |
| |
| /* Set the limiter. |
| */ |
| iEnd = sqlite3VdbeMakeLabel(v); |
| p->nSelectRow = (double)LARGEST_INT64; |
| computeLimitRegisters(pParse, p, iEnd); |
| |
| /* Open a virtual index to use for the distinct set. |
| */ |
| if( p->selFlags & SF_Distinct ){ |
| KeyInfo *pKeyInfo; |
| assert( isAgg || pGroupBy ); |
| distinct = pParse->nTab++; |
| pKeyInfo = keyInfoFromExprList(pParse, p->pEList); |
| sqlite3VdbeAddOp4(v, OP_OpenEphemeral, distinct, 0, 0, |
| (char*)pKeyInfo, P4_KEYINFO_HANDOFF); |
| sqlite3VdbeChangeP5(v, BTREE_UNORDERED); |
| }else{ |
| distinct = -1; |
| } |
| |
| /* Aggregate and non-aggregate queries are handled differently */ |
| if( !isAgg && pGroupBy==0 ){ |
| /* This case is for non-aggregate queries |
| ** Begin the database scan |
| */ |
| pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, &pOrderBy, 0); |
| if( pWInfo==0 ) goto select_end; |
| if( pWInfo->nRowOut < p->nSelectRow ) p->nSelectRow = pWInfo->nRowOut; |
| |
| /* If sorting index that was created by a prior OP_OpenEphemeral |
| ** instruction ended up not being needed, then change the OP_OpenEphemeral |
| ** into an OP_Noop. |
| */ |
| if( addrSortIndex>=0 && pOrderBy==0 ){ |
| sqlite3VdbeChangeToNoop(v, addrSortIndex, 1); |
| p->addrOpenEphm[2] = -1; |
| } |
| |
| /* Use the standard inner loop |
| */ |
| assert(!isDistinct); |
| selectInnerLoop(pParse, p, pEList, 0, 0, pOrderBy, -1, pDest, |
| pWInfo->iContinue, pWInfo->iBreak); |
| |
| /* End the database scan loop. |
| */ |
| sqlite3WhereEnd(pWInfo); |
| }else{ |
| /* This is the processing for aggregate queries */ |
| NameContext sNC; /* Name context for processing aggregate information */ |
| int iAMem; /* First Mem address for storing current GROUP BY */ |
| int iBMem; /* First Mem address for previous GROUP BY */ |
| int iUseFlag; /* Mem address holding flag indicating that at least |
| ** one row of the input to the aggregator has been |
| ** processed */ |
| int iAbortFlag; /* Mem address which causes query abort if positive */ |
| int groupBySort; /* Rows come from source in GROUP BY order */ |
| int addrEnd; /* End of processing for this SELECT */ |
| |
| /* Remove any and all aliases between the result set and the |
| ** GROUP BY clause. |
| */ |
| if( pGroupBy ){ |
| int k; /* Loop counter */ |
| struct ExprList_item *pItem; /* For looping over expression in a list */ |
| |
| for(k=p->pEList->nExpr, pItem=p->pEList->a; k>0; k--, pItem++){ |
| pItem->iAlias = 0; |
| } |
| for(k=pGroupBy->nExpr, pItem=pGroupBy->a; k>0; k--, pItem++){ |
| pItem->iAlias = 0; |
| } |
| if( p->nSelectRow>(double)100 ) p->nSelectRow = (double)100; |
| }else{ |
| p->nSelectRow = (double)1; |
| } |
| |
| |
| /* Create a label to jump to when we want to abort the query */ |
| addrEnd = sqlite3VdbeMakeLabel(v); |
| |
| /* Convert TK_COLUMN nodes into TK_AGG_COLUMN and make entries in |
| ** sAggInfo for all TK_AGG_FUNCTION nodes in expressions of the |
| ** SELECT statement. |
| */ |
| memset(&sNC, 0, sizeof(sNC)); |
| sNC.pParse = pParse; |
| sNC.pSrcList = pTabList; |
| sNC.pAggInfo = &sAggInfo; |
| sAggInfo.nSortingColumn = pGroupBy ? pGroupBy->nExpr+1 : 0; |
| sAggInfo.pGroupBy = pGroupBy; |
| sqlite3ExprAnalyzeAggList(&sNC, pEList); |
| sqlite3ExprAnalyzeAggList(&sNC, pOrderBy); |
| if( pHaving ){ |
| sqlite3ExprAnalyzeAggregates(&sNC, pHaving); |
| } |
| sAggInfo.nAccumulator = sAggInfo.nColumn; |
| for(i=0; i<sAggInfo.nFunc; i++){ |
| assert( !ExprHasProperty(sAggInfo.aFunc[i].pExpr, EP_xIsSelect) ); |
| sqlite3ExprAnalyzeAggList(&sNC, sAggInfo.aFunc[i].pExpr->x.pList); |
| } |
| if( db->mallocFailed ) goto select_end; |
| |
| /* Processing for aggregates with GROUP BY is very different and |
| ** much more complex than aggregates without a GROUP BY. |
| */ |
| if( pGroupBy ){ |
| KeyInfo *pKeyInfo; /* Keying information for the group by clause */ |
| int j1; /* A-vs-B comparision jump */ |
| int addrOutputRow; /* Start of subroutine that outputs a result row */ |
| int regOutputRow; /* Return address register for output subroutine */ |
| int addrSetAbort; /* Set the abort flag and return */ |
| int addrTopOfLoop; /* Top of the input loop */ |
| int addrSortingIdx; /* The OP_OpenEphemeral for the sorting index */ |
| int addrReset; /* Subroutine for resetting the accumulator */ |
| int regReset; /* Return address register for reset subroutine */ |
| |
| /* If there is a GROUP BY clause we might need a sorting index to |
| ** implement it. Allocate that sorting index now. If it turns out |
| ** that we do not need it after all, the OpenEphemeral instruction |
| ** will be converted into a Noop. |
| */ |
| sAggInfo.sortingIdx = pParse->nTab++; |
| pKeyInfo = keyInfoFromExprList(pParse, pGroupBy); |
| addrSortingIdx = sqlite3VdbeAddOp4(v, OP_OpenEphemeral, |
| sAggInfo.sortingIdx, sAggInfo.nSortingColumn, |
| 0, (char*)pKeyInfo, P4_KEYINFO_HANDOFF); |
| |
| /* Initialize memory locations used by GROUP BY aggregate processing |
| */ |
| iUseFlag = ++pParse->nMem; |
| iAbortFlag = ++pParse->nMem; |
| regOutputRow = ++pParse->nMem; |
| addrOutputRow = sqlite3VdbeMakeLabel(v); |
| regReset = ++pParse->nMem; |
| addrReset = sqlite3VdbeMakeLabel(v); |
| iAMem = pParse->nMem + 1; |
| pParse->nMem += pGroupBy->nExpr; |
| iBMem = pParse->nMem + 1; |
| pParse->nMem += pGroupBy->nExpr; |
| sqlite3VdbeAddOp2(v, OP_Integer, 0, iAbortFlag); |
| VdbeComment((v, "clear abort flag")); |
| sqlite3VdbeAddOp2(v, OP_Integer, 0, iUseFlag); |
| VdbeComment((v, "indicate accumulator empty")); |
| |
| /* Begin a loop that will extract all source rows in GROUP BY order. |
| ** This might involve two separate loops with an OP_Sort in between, or |
| ** it might be a single loop that uses an index to extract information |
| ** in the right order to begin with. |
| */ |
| sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset); |
| pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, &pGroupBy, 0); |
| if( pWInfo==0 ) goto select_end; |
| if( pGroupBy==0 ){ |
| /* The optimizer is able to deliver rows in group by order so |
| ** we do not have to sort. The OP_OpenEphemeral table will be |
| ** cancelled later because we still need to use the pKeyInfo |
| */ |
| pGroupBy = p->pGroupBy; |
| groupBySort = 0; |
| }else{ |
| /* Rows are coming out in undetermined order. We have to push |
| ** each row into a sorting index, terminate the first loop, |
| ** then loop over the sorting index in order to get the output |
| ** in sorted order |
| */ |
| int regBase; |
| int regRecord; |
| int nCol; |
| int nGroupBy; |
| |
| explainTempTable(pParse, |
| isDistinct && !(p->selFlags&SF_Distinct)?"DISTINCT":"GROUP BY"); |
| |
| groupBySort = 1; |
| nGroupBy = pGroupBy->nExpr; |
| nCol = nGroupBy + 1; |
| j = nGroupBy+1; |
| for(i=0; i<sAggInfo.nColumn; i++){ |
| if( sAggInfo.aCol[i].iSorterColumn>=j ){ |
| nCol++; |
| j++; |
| } |
| } |
| regBase = sqlite3GetTempRange(pParse, nCol); |
| sqlite3ExprCacheClear(pParse); |
| sqlite3ExprCodeExprList(pParse, pGroupBy, regBase, 0); |
| sqlite3VdbeAddOp2(v, OP_Sequence, sAggInfo.sortingIdx,regBase+nGroupBy); |
| j = nGroupBy+1; |
| for(i=0; i<sAggInfo.nColumn; i++){ |
| struct AggInfo_col *pCol = &sAggInfo.aCol[i]; |
| if( pCol->iSorterColumn>=j ){ |
| int r1 = j + regBase; |
| int r2; |
| |
| r2 = sqlite3ExprCodeGetColumn(pParse, |
| pCol->pTab, pCol->iColumn, pCol->iTable, r1); |
| if( r1!=r2 ){ |
| sqlite3VdbeAddOp2(v, OP_SCopy, r2, r1); |
| } |
| j++; |
| } |
| } |
| regRecord = sqlite3GetTempReg(pParse); |
| sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regRecord); |
| sqlite3VdbeAddOp2(v, OP_IdxInsert, sAggInfo.sortingIdx, regRecord); |
| sqlite3ReleaseTempReg(pParse, regRecord); |
| sqlite3ReleaseTempRange(pParse, regBase, nCol); |
| sqlite3WhereEnd(pWInfo); |
| sqlite3VdbeAddOp2(v, OP_Sort, sAggInfo.sortingIdx, addrEnd); |
| VdbeComment((v, "GROUP BY sort")); |
| sAggInfo.useSortingIdx = 1; |
| sqlite3ExprCacheClear(pParse); |
| } |
| |
| /* Evaluate the current GROUP BY terms and store in b0, b1, b2... |
| ** (b0 is memory location iBMem+0, b1 is iBMem+1, and so forth) |
| ** Then compare the current GROUP BY terms against the GROUP BY terms |
| ** from the previous row currently stored in a0, a1, a2... |
| */ |
| addrTopOfLoop = sqlite3VdbeCurrentAddr(v); |
| sqlite3ExprCacheClear(pParse); |
| for(j=0; j<pGroupBy->nExpr; j++){ |
| if( groupBySort ){ |
| sqlite3VdbeAddOp3(v, OP_Column, sAggInfo.sortingIdx, j, iBMem+j); |
| }else{ |
| sAggInfo.directMode = 1; |
| sqlite3ExprCode(pParse, pGroupBy->a[j].pExpr, iBMem+j); |
| } |
| } |
| sqlite3VdbeAddOp4(v, OP_Compare, iAMem, iBMem, pGroupBy->nExpr, |
| (char*)pKeyInfo, P4_KEYINFO); |
| j1 = sqlite3VdbeCurrentAddr(v); |
| sqlite3VdbeAddOp3(v, OP_Jump, j1+1, 0, j1+1); |
| |
| /* Generate code that runs whenever the GROUP BY changes. |
| ** Changes in the GROUP BY are detected by the previous code |
| ** block. If there were no changes, this block is skipped. |
| ** |
| ** This code copies current group by terms in b0,b1,b2,... |
| ** over to a0,a1,a2. It then calls the output subroutine |
| ** and resets the aggregate accumulator registers in preparation |
| ** for the next GROUP BY batch. |
| */ |
| sqlite3ExprCodeMove(pParse, iBMem, iAMem, pGroupBy->nExpr); |
| sqlite3VdbeAddOp2(v, OP_Gosub, regOutputRow, addrOutputRow); |
| VdbeComment((v, "output one row")); |
| sqlite3VdbeAddOp2(v, OP_IfPos, iAbortFlag, addrEnd); |
| VdbeComment((v, "check abort flag")); |
| sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset); |
| VdbeComment((v, "reset accumulator")); |
| |
| /* Update the aggregate accumulators based on the content of |
| ** the current row |
| */ |
| sqlite3VdbeJumpHere(v, j1); |
| updateAccumulator(pParse, &sAggInfo); |
| sqlite3VdbeAddOp2(v, OP_Integer, 1, iUseFlag); |
| VdbeComment((v, "indicate data in accumulator")); |
| |
| /* End of the loop |
| */ |
| if( groupBySort ){ |
| sqlite3VdbeAddOp2(v, OP_Next, sAggInfo.sortingIdx, addrTopOfLoop); |
| }else{ |
| sqlite3WhereEnd(pWInfo); |
| sqlite3VdbeChangeToNoop(v, addrSortingIdx, 1); |
| } |
| |
| /* Output the final row of result |
| */ |
| sqlite3VdbeAddOp2(v, OP_Gosub, regOutputRow, addrOutputRow); |
| VdbeComment((v, "output final row")); |
| |
| /* Jump over the subroutines |
| */ |
| sqlite3VdbeAddOp2(v, OP_Goto, 0, addrEnd); |
| |
| /* Generate a subroutine that outputs a single row of the result |
| ** set. This subroutine first looks at the iUseFlag. If iUseFlag |
| ** is less than or equal to zero, the subroutine is a no-op. If |
| ** the processing calls for the query to abort, this subroutine |
| ** increments the iAbortFlag memory location before returning in |
| ** order to signal the caller to abort. |
| */ |
| addrSetAbort = sqlite3VdbeCurrentAddr(v); |
| sqlite3VdbeAddOp2(v, OP_Integer, 1, iAbortFlag); |
| VdbeComment((v, "set abort flag")); |
| sqlite3VdbeAddOp1(v, OP_Return, regOutputRow); |
| sqlite3VdbeResolveLabel(v, addrOutputRow); |
| addrOutputRow = sqlite3VdbeCurrentAddr(v); |
| sqlite3VdbeAddOp2(v, OP_IfPos, iUseFlag, addrOutputRow+2); |
| VdbeComment((v, "Groupby result generator entry point")); |
| sqlite3VdbeAddOp1(v, OP_Return, regOutputRow); |
| finalizeAggFunctions(pParse, &sAggInfo); |
| sqlite3ExprIfFalse(pParse, pHaving, addrOutputRow+1, SQLITE_JUMPIFNULL); |
| selectInnerLoop(pParse, p, p->pEList, 0, 0, pOrderBy, |
| distinct, pDest, |
| addrOutputRow+1, addrSetAbort); |
| sqlite3VdbeAddOp1(v, OP_Return, regOutputRow); |
| VdbeComment((v, "end groupby result generator")); |
| |
| /* Generate a subroutine that will reset the group-by accumulator |
| */ |
| sqlite3VdbeResolveLabel(v, addrReset); |
| resetAccumulator(pParse, &sAggInfo); |
| sqlite3VdbeAddOp1(v, OP_Return, regReset); |
| |
| } /* endif pGroupBy. Begin aggregate queries without GROUP BY: */ |
| else { |
| ExprList *pDel = 0; |
| #ifndef SQLITE_OMIT_BTREECOUNT |
| Table *pTab; |
| if( (pTab = isSimpleCount(p, &sAggInfo))!=0 ){ |
| /* If isSimpleCount() returns a pointer to a Table structure, then |
| ** the SQL statement is of the form: |
| ** |
| ** SELECT count(*) FROM <tbl> |
| ** |
| ** where the Table structure returned represents table <tbl>. |
| ** |
| ** This statement is so common that it is optimized specially. The |
| ** OP_Count instruction is executed either on the intkey table that |
| ** contains the data for table <tbl> or on one of its indexes. It |
| ** is better to execute the op on an index, as indexes are almost |
| ** always spread across less pages than their corresponding tables. |
| */ |
| const int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema); |
| const int iCsr = pParse->nTab++; /* Cursor to scan b-tree */ |
| Index *pIdx; /* Iterator variable */ |
| KeyInfo *pKeyInfo = 0; /* Keyinfo for scanned index */ |
| Index *pBest = 0; /* Best index found so far */ |
| int iRoot = pTab->tnum; /* Root page of scanned b-tree */ |
| |
| sqlite3CodeVerifySchema(pParse, iDb); |
| sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName); |
| |
| /* Search for the index that has the least amount of columns. If |
| ** there is such an index, and it has less columns than the table |
| ** does, then we can assume that it consumes less space on disk and |
| ** will therefore be cheaper to scan to determine the query result. |
| ** In this case set iRoot to the root page number of the index b-tree |
| ** and pKeyInfo to the KeyInfo structure required to navigate the |
| ** index. |
| ** |
| ** In practice the KeyInfo structure will not be used. It is only |
| ** passed to keep OP_OpenRead happy. |
| */ |
| for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ |
| if( !pBest || pIdx->nColumn<pBest->nColumn ){ |
| pBest = pIdx; |
| } |
| } |
| if( pBest && pBest->nColumn<pTab->nCol ){ |
| iRoot = pBest->tnum; |
| pKeyInfo = sqlite3IndexKeyinfo(pParse, pBest); |
| } |
| |
| /* Open a read-only cursor, execute the OP_Count, close the cursor. */ |
| sqlite3VdbeAddOp3(v, OP_OpenRead, iCsr, iRoot, iDb); |
| if( pKeyInfo ){ |
| sqlite3VdbeChangeP4(v, -1, (char *)pKeyInfo, P4_KEYINFO_HANDOFF); |
| } |
| sqlite3VdbeAddOp2(v, OP_Count, iCsr, sAggInfo.aFunc[0].iMem); |
| sqlite3VdbeAddOp1(v, OP_Close, iCsr); |
| explainSimpleCount(pParse, pTab, pBest); |
| }else |
| #endif /* SQLITE_OMIT_BTREECOUNT */ |
| { |
| /* Check if the query is of one of the following forms: |
| ** |
| ** SELECT min(x) FROM ... |
| ** SELECT max(x) FROM ... |
| ** |
| ** If it is, then ask the code in where.c to attempt to sort results |
| ** as if there was an "ORDER ON x" or "ORDER ON x DESC" clause. |
| ** If where.c is able to produce results sorted in this order, then |
| ** add vdbe code to break out of the processing loop after the |
| ** first iteration (since the first iteration of the loop is |
| ** guaranteed to operate on the row with the minimum or maximum |
| ** value of x, the only row required). |
| ** |
| ** A special flag must be passed to sqlite3WhereBegin() to slightly |
| ** modify behaviour 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 |
| ** for x. |
| ** |
| ** + The optimizer code in where.c (the thing that decides which |
| ** index or indices to use) should place a different priority on |
| ** satisfying the 'ORDER BY' clause than it does in other cases. |
| ** Refer to code and comments in where.c for details. |
| */ |
| ExprList *pMinMax = 0; |
| u8 flag = minMaxQuery(p); |
| if( flag ){ |
| assert( !ExprHasProperty(p->pEList->a[0].pExpr, EP_xIsSelect) ); |
| pMinMax = sqlite3ExprListDup(db, p->pEList->a[0].pExpr->x.pList,0); |
| pDel = pMinMax; |
| if( pMinMax && !db->mallocFailed ){ |
| pMinMax->a[0].sortOrder = flag!=WHERE_ORDERBY_MIN ?1:0; |
| pMinMax->a[0].pExpr->op = TK_COLUMN; |
| } |
| } |
| |
| /* This case runs if the aggregate has no GROUP BY clause. The |
| ** processing is much simpler since there is only a single row |
| ** of output. |
| */ |
| resetAccumulator(pParse, &sAggInfo); |
| pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, &pMinMax, flag); |
| if( pWInfo==0 ){ |
| sqlite3ExprListDelete(db, pDel); |
| goto select_end; |
| } |
| updateAccumulator(pParse, &sAggInfo); |
| if( !pMinMax && flag ){ |
| sqlite3VdbeAddOp2(v, OP_Goto, 0, pWInfo->iBreak); |
| VdbeComment((v, "%s() by index", |
| (flag==WHERE_ORDERBY_MIN?"min":"max"))); |
| } |
| sqlite3WhereEnd(pWInfo); |
| finalizeAggFunctions(pParse, &sAggInfo); |
| } |
| |
| pOrderBy = 0; |
| sqlite3ExprIfFalse(pParse, pHaving, addrEnd, SQLITE_JUMPIFNULL); |
| selectInnerLoop(pParse, p, p->pEList, 0, 0, 0, -1, |
| pDest, addrEnd, addrEnd); |
| sqlite3ExprListDelete(db, pDel); |
| } |
| sqlite3VdbeResolveLabel(v, addrEnd); |
| |
| } /* endif aggregate query */ |
| |
| if( distinct>=0 ){ |
| explainTempTable(pParse, "DISTINCT"); |
| } |
| |
| /* If there is an ORDER BY clause, then we need to sort the results |
| ** and send them to the callback one by one. |
| */ |
| if( pOrderBy ){ |
| explainTempTable(pParse, "ORDER BY"); |
| generateSortTail(pParse, p, v, pEList->nExpr, pDest); |
| } |
| |
| /* Jump here to skip this query |
| */ |
| sqlite3VdbeResolveLabel(v, iEnd); |
| |
| /* The SELECT was successfully coded. Set the return code to 0 |
| ** to indicate no errors. |
| */ |
| rc = 0; |
| |
| /* Control jumps to here if an error is encountered above, or upon |
| ** successful coding of the SELECT. |
| */ |
| select_end: |
| explainSetInteger(pParse->iSelectId, iRestoreSelectId); |
| |
| /* Identify column names if results of the SELECT are to be output. |
| */ |
| if( rc==SQLITE_OK && pDest->eDest==SRT_Output ){ |
| generateColumnNames(pParse, pTabList, pEList); |
| } |
| |
| sqlite3DbFree(db, sAggInfo.aCol); |
| sqlite3DbFree(db, sAggInfo.aFunc); |
| return rc; |
| } |
| |
| #if defined(SQLITE_DEBUG) |
| /* |
| ******************************************************************************* |
| ** The following code is used for testing and debugging only. The code |
| ** that follows does not appear in normal builds. |
| ** |
| ** These routines are used to print out the content of all or part of a |
| ** parse structures such as Select or Expr. Such printouts are useful |
| ** for helping to understand what is happening inside the code generator |
| ** during the execution of complex SELECT statements. |
| ** |
| ** These routine are not called anywhere from within the normal |
| ** code base. Then are intended to be called from within the debugger |
| ** or from temporary "printf" statements inserted for debugging. |
| */ |
| void sqlite3PrintExpr(Expr *p){ |
| if( !ExprHasProperty(p, EP_IntValue) && p->u.zToken ){ |
| sqlite3DebugPrintf("(%s", p->u.zToken); |
| }else{ |
| sqlite3DebugPrintf("(%d", p->op); |
| } |
| if( p->pLeft ){ |
| sqlite3DebugPrintf(" "); |
| sqlite3PrintExpr(p->pLeft); |
| } |
| if( p->pRight ){ |
| sqlite3DebugPrintf(" "); |
| sqlite3PrintExpr(p->pRight); |
| } |
| sqlite3DebugPrintf(")"); |
| } |
| void sqlite3PrintExprList(ExprList *pList){ |
| int i; |
| for(i=0; i<pList->nExpr; i++){ |
| sqlite3PrintExpr(pList->a[i].pExpr); |
| if( i<pList->nExpr-1 ){ |
| sqlite3DebugPrintf(", "); |
| } |
| } |
| } |
| void sqlite3PrintSelect(Select *p, int indent){ |
| sqlite3DebugPrintf("%*sSELECT(%p) ", indent, "", p); |
| sqlite3PrintExprList(p->pEList); |
| sqlite3DebugPrintf("\n"); |
| if( p->pSrc ){ |
| char *zPrefix; |
| int i; |
| zPrefix = "FROM"; |
| for(i=0; i<p->pSrc->nSrc; i++){ |
| struct SrcList_item *pItem = &p->pSrc->a[i]; |
| sqlite3DebugPrintf("%*s ", indent+6, zPrefix); |
| zPrefix = ""; |
| if( pItem->pSelect ){ |
| sqlite3DebugPrintf("(\n"); |
| sqlite3PrintSelect(pItem->pSelect, indent+10); |
| sqlite3DebugPrintf("%*s)", indent+8, ""); |
| }else if( pItem->zName ){ |
| sqlite3DebugPrintf("%s", pItem->zName); |
| } |
| if( pItem->pTab ){ |
| sqlite3DebugPrintf("(table: %s)", pItem->pTab->zName); |
| } |
| if( pItem->zAlias ){ |
| sqlite3DebugPrintf(" AS %s", pItem->zAlias); |
| } |
| if( i<p->pSrc->nSrc-1 ){ |
| sqlite3DebugPrintf(","); |
| } |
| sqlite3DebugPrintf("\n"); |
| } |
| } |
| if( p->pWhere ){ |
| sqlite3DebugPrintf("%*s WHERE ", indent, ""); |
| sqlite3PrintExpr(p->pWhere); |
| sqlite3DebugPrintf("\n"); |
| } |
| if( p->pGroupBy ){ |
| sqlite3DebugPrintf("%*s GROUP BY ", indent, ""); |
| sqlite3PrintExprList(p->pGroupBy); |
| sqlite3DebugPrintf("\n"); |
| } |
| if( p->pHaving ){ |
| sqlite3DebugPrintf("%*s HAVING ", indent, ""); |
| sqlite3PrintExpr(p->pHaving); |
| sqlite3DebugPrintf("\n"); |
| } |
| if( p->pOrderBy ){ |
| sqlite3DebugPrintf("%*s ORDER BY ", indent, ""); |
| sqlite3PrintExprList(p->pOrderBy); |
| sqlite3DebugPrintf("\n"); |
| } |
| } |
| /* End of the structure debug printing code |
| *****************************************************************************/ |
| #endif /* defined(SQLITE_TEST) || defined(SQLITE_DEBUG) */ |