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Merge the nested aggregate query enhancements into trunk.

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FossilOrigin-Name: d4cd6017c9875947a05b1dc36538d4272fb18739
This commit is contained in:
drh
2012-08-24 01:07:52 +00:00
parent 319a170717 ed551b95a4
commit fb0a60819b
8 changed files with 200 additions and 53 deletions
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73
src/expr.c
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@@ -3123,9 +3123,12 @@ void sqlite3ExplainExpr(Vdbe *pOut, Expr *pExpr){
}else{
pFarg = pExpr->x.pList;
}
sqlite3ExplainPrintf(pOut, "%sFUNCTION:%s(",
op==TK_AGG_FUNCTION ? "AGG_" : "",
pExpr->u.zToken);
if( op==TK_AGG_FUNCTION ){
sqlite3ExplainPrintf(pOut, "AGG_FUNCTION%d:%s(",
pExpr->op2, pExpr->u.zToken);
}else{
sqlite3ExplainPrintf(pOut, "FUNCTION:%s(", pExpr->u.zToken);
}
if( pFarg ){
sqlite3ExplainExprList(pOut, pFarg);
}
@@ -3816,38 +3819,60 @@ int sqlite3ExprListCompare(ExprList *pA, ExprList *pB){
}
/*
** This is the expression callback for sqlite3FunctionUsesOtherSrc().
**
** Determine if an expression references any table other than one of the
** tables in pWalker->u.pSrcList and abort if it does.
** An instance of the following structure is used by the tree walker
** to count references to table columns in the arguments of an
** aggregate function, in order to implement the
** sqlite3FunctionThisSrc() routine.
*/
static int exprUsesOtherSrc(Walker *pWalker, Expr *pExpr){
if( pExpr->op==TK_COLUMN || pExpr->op==TK_AGG_COLUMN ){
struct SrcCount {
SrcList *pSrc; /* One particular FROM clause in a nested query */
int nThis; /* Number of references to columns in pSrcList */
int nOther; /* Number of references to columns in other FROM clauses */
};
/*
** Count the number of references to columns.
*/
static int exprSrcCount(Walker *pWalker, Expr *pExpr){
/* The NEVER() on the second term is because sqlite3FunctionUsesThisSrc()
** is always called before sqlite3ExprAnalyzeAggregates() and so the
** TK_COLUMNs have not yet been converted into TK_AGG_COLUMN. If
** sqlite3FunctionUsesThisSrc() is used differently in the future, the
** NEVER() will need to be removed. */
if( pExpr->op==TK_COLUMN || NEVER(pExpr->op==TK_AGG_COLUMN) ){
int i;
SrcList *pSrc = pWalker->u.pSrcList;
struct SrcCount *p = pWalker->u.pSrcCount;
SrcList *pSrc = p->pSrc;
for(i=0; i<pSrc->nSrc; i++){
if( pExpr->iTable==pSrc->a[i].iCursor ) return WRC_Continue;
if( pExpr->iTable==pSrc->a[i].iCursor ) break;
}
if( i<pSrc->nSrc ){
p->nThis++;
}else{
p->nOther++;
}
return WRC_Abort;
}else{
return WRC_Continue;
}
return WRC_Continue;
}
/*
** Determine if any of the arguments to the pExpr Function references
** any SrcList other than pSrcList. Return true if they do. Return
** false if pExpr has no argument or has only constant arguments or
** only references tables named in pSrcList.
** Determine if any of the arguments to the pExpr Function reference
** pSrcList. Return true if they do. Also return true if the function
** has no arguments or has only constant arguments. Return false if pExpr
** references columns but not columns of tables found in pSrcList.
*/
static int sqlite3FunctionUsesOtherSrc(Expr *pExpr, SrcList *pSrcList){
int sqlite3FunctionUsesThisSrc(Expr *pExpr, SrcList *pSrcList){
Walker w;
struct SrcCount cnt;
assert( pExpr->op==TK_AGG_FUNCTION );
memset(&w, 0, sizeof(w));
w.xExprCallback = exprUsesOtherSrc;
w.u.pSrcList = pSrcList;
if( sqlite3WalkExprList(&w, pExpr->x.pList)!=WRC_Continue ) return 1;
return 0;
w.xExprCallback = exprSrcCount;
w.u.pSrcCount = &cnt;
cnt.pSrc = pSrcList;
cnt.nThis = 0;
cnt.nOther = 0;
sqlite3WalkExprList(&w, pExpr->x.pList);
return cnt.nThis>0 || cnt.nOther==0;
}
/*
@@ -3966,7 +3991,7 @@ static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
}
case TK_AGG_FUNCTION: {
if( (pNC->ncFlags & NC_InAggFunc)==0
&& !sqlite3FunctionUsesOtherSrc(pExpr, pSrcList)
&& pWalker->walkerDepth==pExpr->op2
){
/* Check to see if pExpr is a duplicate of another aggregate
** function that is already in the pAggInfo structure