diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/select.c | 28 |
1 files changed, 18 insertions, 10 deletions
diff --git a/src/select.c b/src/select.c index 003d42e72..b8ed890b3 100644 --- a/src/select.c +++ b/src/select.c @@ -521,7 +521,7 @@ static void pushOntoSorter( int iLimit; /* LIMIT counter */ assert( bSeq==0 || bSeq==1 ); - assert( nData==1 || regData==regOrigData ); + assert( nData==1 || regData==regOrigData || regOrigData==0 ); if( nPrefixReg ){ assert( nPrefixReg==nExpr+bSeq ); regBase = regData - nExpr - bSeq; @@ -533,7 +533,7 @@ static void pushOntoSorter( iLimit = pSelect->iOffset ? pSelect->iOffset+1 : pSelect->iLimit; pSort->labelDone = sqlite3VdbeMakeLabel(v); sqlite3ExprCodeExprList(pParse, pSort->pOrderBy, regBase, regOrigData, - SQLITE_ECEL_DUP); + SQLITE_ECEL_DUP | (regOrigData? SQLITE_ECEL_REF : 0)); if( bSeq ){ sqlite3VdbeAddOp2(v, OP_Sequence, pSort->iECursor, regBase+nExpr); } @@ -681,13 +681,20 @@ static void selectInnerLoop( ){ Vdbe *v = pParse->pVdbe; int i; - int hasDistinct; /* True if the DISTINCT keyword is present */ - int regResult; /* Start of memory holding result set */ + int hasDistinct; /* True if the DISTINCT keyword is present */ int eDest = pDest->eDest; /* How to dispose of results */ int iParm = pDest->iSDParm; /* First argument to disposal method */ int nResultCol; /* Number of result columns */ int nPrefixReg = 0; /* Number of extra registers before regResult */ + /* Usually, regResult is the first cell in an array of memory cells + ** containing the current result row. In this case regOrig is set to the + ** same value. However, if the results are being sent to the sorter, the + ** values for any expressions that are also part of the sort-key are omitted + ** from this array. In this case regOrig is set to zero. */ + int regResult; /* Start of memory holding current results */ + int regOrig; /* Start of memory holding full result (or 0) */ + assert( v ); assert( pEList!=0 ); hasDistinct = pDistinct ? pDistinct->eTnctType : WHERE_DISTINCT_NOOP; @@ -718,7 +725,7 @@ static void selectInnerLoop( pParse->nMem += nResultCol; } pDest->nSdst = nResultCol; - regResult = pDest->iSdst; + regOrig = regResult = pDest->iSdst; if( srcTab>=0 ){ for(i=0; i<nResultCol; i++){ sqlite3VdbeAddOp3(v, OP_Column, srcTab, i, regResult+i); @@ -734,7 +741,8 @@ static void selectInnerLoop( }else{ ecelFlags = 0; } - if( pSort && hasDistinct==0 && eDest!=SRT_EphemTab && eDest!=SRT_Table ){ + assert( eDest!=SRT_Table || pSort==0 ); + if( pSort && hasDistinct==0 && eDest!=SRT_EphemTab ){ /* For each expression in pEList that is a copy of an expression in ** the ORDER BY clause (pSort->pOrderBy), set the associated ** iOrderByCol value to one more than the index of the ORDER BY @@ -748,7 +756,7 @@ static void selectInnerLoop( pEList->a[j-1].u.x.iOrderByCol = i+1-pSort->nOBSat; } } - + regOrig = 0; assert( eDest==SRT_Set || eDest==SRT_Mem || eDest==SRT_Coroutine || eDest==SRT_Output ); } @@ -892,7 +900,7 @@ static void selectInnerLoop( ** does not matter. But there might be a LIMIT clause, in which ** case the order does matter */ pushOntoSorter( - pParse, pSort, p, regResult, regResult, nResultCol, nPrefixReg); + pParse, pSort, p, regResult, regOrig, nResultCol, nPrefixReg); }else{ int r1 = sqlite3GetTempReg(pParse); assert( sqlite3Strlen30(pDest->zAffSdst)==nResultCol ); @@ -921,7 +929,7 @@ static void selectInnerLoop( if( pSort ){ assert( nResultCol<=pDest->nSdst ); pushOntoSorter( - pParse, pSort, p, regResult, regResult, nResultCol, nPrefixReg); + pParse, pSort, p, regResult, regOrig, nResultCol, nPrefixReg); }else{ assert( nResultCol==pDest->nSdst ); assert( regResult==iParm ); @@ -936,7 +944,7 @@ static void selectInnerLoop( testcase( eDest==SRT_Coroutine ); testcase( eDest==SRT_Output ); if( pSort ){ - pushOntoSorter(pParse, pSort, p, regResult, regResult, nResultCol, + pushOntoSorter(pParse, pSort, p, regResult, regOrig, nResultCol, nPrefixReg); }else if( eDest==SRT_Coroutine ){ sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm); |