** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
-** $Id: select.c,v 1.203 2004/08/21 17:54:45 drh Exp $
+** $Id: select.c,v 1.204 2004/08/29 01:31:05 drh Exp $
*/
#include "sqliteInt.h"
return addr;
}
+/*
+** FIX ME:
+** + Omit the ppOpenTemp parameter from multiSelectOpenTempAddr().
+** + Attach pOpenList to the right-most term always.
+** + Make sure Select.ppOpenTemp is initialized to NULL
+*/
+
+/*
+** Add the address "addr" to the set of all opcode addresses contained
+** in the pOpenTemp list for the whole compound select. If no pOpenTemp
+** list has been created yet, then create a new one and make *ppOpenTemp
+** point to it. If the pOpenTemp list already exists, leave *ppOpenTemp
+** unchanged and just add the new address to the existing list.
+*/
static int multiSelectOpenTempAddr(Select *p, int addr, IdList **ppOpenTemp){
+ IdList *pList;
if( !p->ppOpenTemp ){
+ /* Create a new list */
*ppOpenTemp = sqlite3IdListAppend(0, 0);
p->ppOpenTemp = ppOpenTemp;
}else{
+ /* Add a new element onto the end of the existing list */
*p->ppOpenTemp = sqlite3IdListAppend(*p->ppOpenTemp, 0);
}
- if( !(*p->ppOpenTemp) ){
+ pList = *p->ppOpenTemp;
+ if( pList==0 ){
return SQLITE_NOMEM;
}
- (*p->ppOpenTemp)->a[(*p->ppOpenTemp)->nId-1].idx = addr;
+ pList->a[pList->nId-1].idx = addr;
return SQLITE_OK;
}
+/*
+** 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 = 0;
+ CollSeq *pRet;
if( p->pPrior ){
pRet = multiSelectCollSeq(pParse, p->pPrior, iCol);
+ }else{
+ pRet = 0;
}
- if( !pRet ){
+ if( pRet==0 ){
pRet = sqlite3ExprCollSeq(pParse, p->pEList->a[iCol].pExpr);
}
return pRet;
** individual selects always group from left to right.
*/
static int multiSelect(
- Parse *pParse,
- Select *p,
- int eDest,
- int iParm,
- char *aff /* If eDest is SRT_Union, the affinity string */
+ Parse *pParse, /* Parsing context */
+ Select *p, /* The right-most of SELECTs to be coded */
+ int eDest, /* \___ Store query results as specified */
+ int iParm, /* / by these two parameters. */
+ 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 */
- IdList *pOpenTemp = 0;
+ int rc = SQLITE_OK; /* Success code from a subroutine */
+ Select *pPrior; /* Another SELECT immediately to our left */
+ Vdbe *v; /* Generate code to this VDBE */
+ IdList *pOpenTemp = 0;/* OP_OpenTemp opcodes that need a KeyInfo */
/* Make sure there is no ORDER BY or LIMIT clause on prior SELECTs. Only
- ** the last SELECT in the series may have an ORDER BY or LIMIT.
+ ** the last (right-most) SELECT in the series may have an ORDER BY or LIMIT.
*/
if( p==0 || p->pPrior==0 ){
rc = 1;
goto multi_select_end;
}
+ /* PART OF FIX:
+ */
+ if( p->ppOpenTemp==0 ){
+ p->ppOpenTemp = &pOpenTemp;
+ }
+ pPrior->ppOpenTemp = p->ppOpenTemp;
+
/* Create the destination temporary table if necessary
*/
if( eDest==SRT_TempTable ){
assert( p->pEList );
sqlite3VdbeAddOp(v, OP_OpenTemp, iParm, 0);
+
+ /* FIX ME:
+ ** p->pEList->nExpr might contain a "*" and so might not be the
+ ** correct number. Go ahead and code the SetNumColumns instruction
+ ** here, but also record its address. Change the P2 value of the
+ ** instruction to the number of columns after sqlite3Select() has
+ ** been called to code the subquery and has modified pEList->nExpr
+ ** to be the correct value. */
sqlite3VdbeAddOp(v, OP_SetNumColumns, iParm, p->pEList->nExpr);
eDest = SRT_Table;
}
if( p->pOrderBy==0 ){
pPrior->nLimit = p->nLimit;
pPrior->nOffset = p->nOffset;
- pPrior->ppOpenTemp = p->ppOpenTemp;
+ /* pPrior->ppOpenTemp = p->ppOpenTemp; // FIX */
rc = sqlite3Select(pParse, pPrior, eDest, iParm, 0, 0, 0, aff);
if( rc ){
goto multi_select_end;
/* Code the SELECT statements to our left
*/
- pPrior->ppOpenTemp = p->ppOpenTemp;
+ /* pPrior->ppOpenTemp = p->ppOpenTemp; // FIX */
rc = sqlite3Select(pParse, pPrior, priorOp, unionTab, 0, 0, 0, aff);
if( rc ){
goto multi_select_end;
/* Code the SELECTs to our left into temporary table "tab1".
*/
- pPrior->ppOpenTemp = p->ppOpenTemp;
+ /* pPrior->ppOpenTemp = p->ppOpenTemp; // FIX */
rc = sqlite3Select(pParse, pPrior, SRT_Union, tab1, 0, 0, 0, aff);
if( rc ){
goto multi_select_end;
goto multi_select_end;
}
+ /* Compute collating sequences used by either the ORDER BY clause or
+ ** by any temporary tables needed to implement the compound select.
+ ** Attach the KeyInfo structure to all temporary tables. Invoke the
+ ** ORDER BY processing if there is an ORDER BY clause.
+ */
if( p->pOrderBy || (pOpenTemp && pOpenTemp->nId>0) ){
- int nCol = p->pEList->nExpr;
- int i;
- KeyInfo *pKeyInfo = sqliteMalloc(sizeof(*pKeyInfo)+nCol*sizeof(CollSeq*));
+ int nCol = p->pEList->nExpr; /* Number of columns in the result set */
+ int i; /* Loop counter */
+ KeyInfo *pKeyInfo; /* Collating sequence for the result set */
+
+ pKeyInfo = sqliteMalloc(sizeof(*pKeyInfo)+nCol*sizeof(CollSeq*));
if( !pKeyInfo ){
rc = SQLITE_NOMEM;
goto multi_select_end;
}
if( p->pOrderBy ){
- for(i=0; i<p->pOrderBy->nExpr; i++){
- Expr *pExpr = p->pOrderBy->a[i].pExpr;
- char *zName = p->pOrderBy->a[i].zName;
+ struct ExprList_item *pOrderByTerm = p->pOrderBy->a;
+ for(i=0; i<p->pOrderBy->nExpr; i++, pOrderByTerm++){
+ Expr *pExpr = pOrderByTerm->pExpr;
+ char *zName = pOrderByTerm->zName;
assert( pExpr->op==TK_COLUMN && pExpr->iColumn<nCol );
assert( !pExpr->pColl );
if( zName ){
generateColumnNames(pParse, pTabList, pEList);
}
-#if 1 /* I do not think we need the following code any more.... */
/* If the destination is SRT_Union, then set the number of columns in
** the records that will be inserted into the temporary table. The caller
** couldn't do this, in case the select statement is of the form
if( eDest==SRT_Union ){
sqlite3VdbeAddOp(v, OP_SetNumColumns, iParm, pEList->nExpr);
}
-#endif
/* Generate code for all sub-queries in the FROM clause
*/
projects / thirdparty / sqlite.git / commitdiff
