** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
-** $Id: select.c,v 1.432 2008/06/20 18:13:25 drh Exp $
+** $Id: select.c,v 1.433 2008/06/22 12:37:58 drh Exp $
*/
#include "sqliteInt.h"
int regRecord = sqlite3GetTempReg(pParse);
sqlite3ExprCodeExprList(pParse, pOrderBy, regBase, 0);
sqlite3VdbeAddOp2(v, OP_Sequence, pOrderBy->iECursor, regBase+nExpr);
- sqlite3ExprCodeMove(pParse, regData, regBase+nExpr+1);
+ 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);
if( pOrderBy ){
pushOntoSorter(pParse, pOrderBy, p, regResult);
}else{
- sqlite3ExprCodeMove(pParse, regResult, iParm);
+ sqlite3ExprCodeMove(pParse, regResult, iParm, 1);
/* The LIMIT clause will jump out of the loop for us */
}
break;
}
case SRT_Mem: {
assert( nColumn==1 );
- sqlite3ExprCodeMove(pParse, regRow, iParm);
+ sqlite3ExprCodeMove(pParse, regRow, iParm, 1);
/* The LIMIT clause will terminate the loop for us */
break;
}
** Analyze and ORDER BY or GROUP BY clause in a SELECT statement. Return
** the number of errors seen.
**
-** The processing depends on whether the SELECT is simple or compound.
-** For a simple SELECT statement, evry term of the ORDER BY or GROUP BY
-** clause needs to be an expression. If any expression is an integer
-** constant, then that expression is replaced by the corresponding
-** expression from the result set.
-**
** For compound SELECT statements, every expression needs to be of
** type TK_COLUMN with a iTable value as given in the 4th parameter.
** If any expression is an integer, that becomes the column number.
}
#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 */
+ char *aff /* If eDest is SRT_Union, the affinity string */
+);
+
+
#ifndef SQLITE_OMIT_COMPOUND_SELECT
/*
** This routine is called to process a compound query form from
int nSetP2 = 0; /* Number of slots in aSetP2[] used */
SelectDest dest; /* Alternative data destination */
- dest = *pDest;
-
/* 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.
*/
goto multi_select_end;
}
+#if 0
+ if( p->pOrderBy ){
+ return multiSelectOrderBy(pParse, p, pDest, aff);
+ }
+#endif
+
/* Create the destination temporary table if necessary
*/
+ dest = *pDest;
if( dest.eDest==SRT_EphemTab ){
assert( p->pEList );
assert( nSetP2<sizeof(aSetP2)/sizeof(aSetP2[0]) );
}
#endif /* SQLITE_OMIT_COMPOUND_SELECT */
+#if 0 /****** ################ ******/
+/*
+** Code an output subroutine for a coroutine implementation of a
+** SELECT statment.
+*/
+static int outputSubroutine(
+ Parse *pParse,
+ SelectDest *pIn
+ SelectDest *pDest
+){
+ Vdbe *v = pParse->pVdbe;
+ if( v==0 ) return;
+
+ if( pDest->iMem==0 ){
+ pDest->iMem = sqlite3GetTempRange(pParse, pIn->nMem);
+ pDest->nMem = nResultCol;
+ }
+
+ 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);
+ sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nColumn, r1);
+ 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: {
+ int addr2, r1;
+ assert( nColumn==1 );
+ addr2 = sqlite3VdbeAddOp1(v, OP_IsNull, regResult);
+ p->affinity = sqlite3CompareAffinity(pEList->a[0].pExpr, pDest->affinity);
+ 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);
+ sqlite3VdbeJumpHere(v, addr2);
+ 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 );
+ 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_Callback: {
+ if( eDest==SRT_Coroutine ){
+ sqlite3VdbeAddOp1(v, OP_Yield, pDest->regCoroutine);
+ }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: {
+ break;
+ }
+#endif
+ }
+}
+
+/*
+** 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 while A==B
+**
+** AgtB: outB, nextB outB, nextB nextB nextB
+**
+** EofA: outB, nextB A<-B, outB, halt halt
+** nextB while A==B
+**
+** EofB: outA, nextA B<-A, outA outA, nextA halt
+** nextA while A==B
+**
+** 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.
+*/
+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 */
+ char *aff /* If eDest is SRT_Union, the affinity string */
+){
+ int rc = SQLITE_OK; /* Success code from a subroutine */
+ Select *pPrior; /* Another SELECT immediately to our left */
+ Vdbe *v; /* Generate code to this VDBE */
+ int nCol; /* Number of columns in the result set */
+ ExprList *pOrderBy; /* The ORDER BY clause on p */
+ int aSetP2[2]; /* Set P2 value of these op to number of columns */
+ int nSetP2 = 0; /* Number of slots in aSetP2[] used */
+ SelectDest destA; /* Destination for coroutine A */
+ SelectDest destB; /* Destination for coroutine B */
+ int regAddrA;
+ int regEofA;
+ int regAddrB;
+ int regEofB;
+ int addrSelectA;
+ int addrSelectB;
+ int regOutA;
+ int regOutB;
+ int addrOutA;
+ int addrOutB;
+ int addrEofA;
+ int addrEofB;
+ int addrAltB;
+ int addrAeqB;
+ int addrAgtB;
+ int labelCmpr;
+ int labelEnd;
+ int j1, j2, j3;
+
+ /* Patch up the ORDER BY clause */
+
+ pPrior = p->pPrior;
+ 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);
+
+ j1 = sqlite3VdbeAddOp0(v, OP_Goto);
+ addrSelectA = sqlite3VdbeCurrentAddr(v);
+ VdbeNoopComment((v, "Begin coroutine for left SELECT"));
+ sqlite3SelectDestInit(&destA, SRT_Coroutine, 0);
+ sqlite3Select();
+ sqlite3VdbeAddOp2(v, OP_Integer, 1, regEofA);
+ sqlite3VdbeAddOp2(v, OP_Yield, regAddrA);
+ VdbeNoopComment((v, "End coroutine for left SELECT"));
+
+ addrSelectB = sqlite3VdbeCurrentAddr(v);
+ VdbeNoopComment((v, "Begin coroutine for right SELECT"));
+ sqlite3SelectDestInit(&destB, SRT_Coroutine, 0);
+ sqlite3Select();
+ sqlite3VdbeAddOp2(v, OP_Integer, 1, regEofB);
+ sqlite3VdbeAddOp2(v, OP_Yield, regAddrB);
+ VdbeNoopComment((v, "End coroutine for right SELECT"));
+
+ VdbeNoopComment((v, "Output routine for A"));
+ addrOutA = outputSubroutine(pParse, &destA, pDest);
+
+ VdbeNoopComment((v, "Output routine for B"));
+ addrOutB = outputSubroutine(pParse, &destB, pDest);
+
+ if( op==TK_EXCEPT || op==TK_INTERSECT ){
+ addrEofA = iEnd;
+ }else{
+ VdbeNoopCommment((v, "eof-A subroutine"));
+ addrEofA = sqlite3VdbeCurrentAddr(v);
+ if( op==TK_ALL ){
+ j2 = sqlite3VdbeAddOp2(v, OP_If, regEofB, labelEnd);
+ sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB);
+ sqlite3VdbeAddOp1(v, OP_Yield, regAddrB);
+ sqlite3VdbeAddOp2(v, OP_Goto, 0, j2);
+ }else{
+ assert( op==TK_UNION );
+ sqlite3VdbeAddOp2(v, OP_If, regEofB, labelEnd);
+ sqlite3ExprCodeMove(pParse, destB.iMem, destA.iMem, destB.nMem);
+ j2 = sqlite3VdbeAddOp2(v, OP_Gosub, regOutB, addrOutB);
+ sqlite3VdbeAddOp1(v, OP_Yield, regAddrB);
+ sqlite3VdbeAddOp2(v, OP_If, regEofB, labelEnd);
+ sqlite3VdbeAddOp3(v, OP_Compare, destA.iMem, destB.iMem, destB.nMem);
+ sqlite3VdbeAddOp3(v, OP_Jump, j2, j2+1, j2);
+ }
+ }
+
+
+ if( op==TK_INTERSECT ){
+ addrEofA = iEnd;
+ }else{
+ VdbeNoopCommment((v, "eof-B subroutine"));
+ addrEofA = sqlite3VdbeCurrentAddr(v);
+ if( op==TK_ALL || op==TK_EXCEPT ){
+ j2 = sqlite3VdbeAddOp2(v, OP_If, regEofA, labelEnd);
+ sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA);
+ sqlite3VdbeAddOp1(v, OP_Yield, regAddrA);
+ sqlite3VdbeAddOp2(v, OP_Goto, 0, j2);
+ }else{
+ assert( op==TK_UNION );
+ sqlite3VdbeAddOp2(v, OP_If, regEofA, labelEnd);
+ sqlite3ExprCodeMove(pParse, destA.iMem, destB.iMem, destA.nMem);
+ j2 = sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA);
+ sqlite3VdbeAddOp1(v, OP_Yield, regAddrA);
+ sqlite3VdbeAddOp2(v, OP_If, regEofA, labelEnd);
+ sqlite3VdbeAddOp3(v, OP_Compare, destA.iMem, destB.iMem, destB.nMem);
+ sqlite3VdbeAddOp3(v, OP_Jump, j2, j2+1, j2);
+ }
+ }
+
+ VdbeNoopComment((v, "A-lt-B subroutine"));
+ addrAltB = sqlite3VdbeCurrentAddr(v);
+ if( op!=TK_INTERSECT ){
+ sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA);
+ }
+ addrAeqB = sqlite3VdbeAddOp1(v, OP_Yield, regAddrA);
+ sqlite3VdbeAddOp2(v, OP_If, regEofA, addrEofA);
+ sqlite3VdbeAddOp2(v, OP_Goto, 0, labelCompare);
+
+ if( op==TK_ALL ){
+ addrAeqB = addrAltB;
+ }else if( op==TK_INTERSECT ){
+ VdbeNoopComment((v, "A-eq-B subroutine"));
+ sqlite3VdbeAddOp2(v, OP_Gosub, regOutA, addrOutA);
+ j2 = sqlite3VdbeAddOp1(v, OP_Yield, regAddrA);
+ sqlite3VdbeAddOp2(v, OP_If, regEofA, addrEofA);
+ sqlite3VdbeAddOp4(v, OP_Compare, destA.iMem, destB.iMem, destA.iMem,
+ pKeyInfo, P4_KEYINFO_STATIC);
+ j3 = sqlite3VdbeCurrentAddr(v)+1;
+ sqlite3VdbeAddOp3(v, OP_Jump, j3, j2, j3);
+ sqlite3VdbeAddOp2(v, OP_Goto, 0, labelCompare);
+ }
+
+ 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, labelCompare);
+
+ sqlite3VdbeJumpHere(v, j1);
+ sqlite3VdbeAddOp2(v, OP_Integer, 0, regEofA);
+ sqlite3VdbeAddOp2(v, OP_Integer, 0, regEofB);
+ sqlite3VdbeAddOp2(v, OP_Integer, addrSelectA, regAddrA);
+ sqlite3VdbeAddOp2(v, OP_Integer, addrSelectB, regAddrB);
+ sqlite3VdbeAddOp1(v, OP_Yield, regAddrA);
+ sqlite3VdbeAddOp2(v, OP_If, regEofA, addrEofA);
+ sqlite3VdbeAddOp1(v, OP_Yield, regAddrB);
+ sqlite3VdbeAddOp2(v, OP_If, regEofB, addrEofB);
+ sqlite3VdbeResolve(v, labelCompare);
+ sqlite3VdbeAddOp4(v, OP_Compare, destA.iMem, destB.iMem, destA.iMem,
+ pKeyInfo, P4_KEYINFO_HANDOFF);
+ sqlite3VdbeAddOp3(v, OP_Jump, addrAltB, addrAeqB, addrAgtB);
+ sqlite3VdbeResolveLabel(v, labelEnd);
+
+}
+#endif /***** ########### *****/
+
#ifndef SQLITE_OMIT_VIEW
/* Forward Declarations */
static void substExprList(sqlite3*, ExprList*, int, ExprList*);
}
}
sqlite3VdbeAddOp4(v, OP_Compare, iAMem, iBMem, pGroupBy->nExpr,
- (char*)pKeyInfo, P4_KEYINFO_STATIC);
+ (char*)pKeyInfo, P4_KEYINFO);
j1 = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp3(v, OP_Jump, j1+1, 0, j1+1);
** and resets the aggregate accumulator registers in preparation
** for the next GROUP BY batch.
*/
- for(j=0; j<pGroupBy->nExpr; j++){
- sqlite3ExprCodeMove(pParse, iBMem+j, iAMem+j);
- }
+ sqlite3ExprCodeMove(pParse, iBMem, iAMem, pGroupBy->nExpr);
sqlite3VdbeAddOp2(v, OP_Gosub, regOutputRow, addrOutputRow);
VdbeComment((v, "output one row"));
sqlite3VdbeAddOp2(v, OP_IfPos, iAbortFlag, addrEnd);
projects / thirdparty / sqlite.git / commitdiff
