Merge the nested aggregate query enhancements into trunk.
FossilOrigin-Name: d4cd6017c9875947a05b1dc36538d4272fb18739
diff --git a/src/expr.c b/src/expr.c
index 790aa45..89172f9 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -3123,9 +3123,12 @@
}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 @@
}
/*
-** 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;
}
- return WRC_Abort;
- }else{
- return WRC_Continue;
+ if( i<pSrc->nSrc ){
+ p->nThis++;
+ }else{
+ p->nOther++;
+ }
}
+ 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 @@
}
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
diff --git a/src/resolve.c b/src/resolve.c
index a66f88f..b87d231 100644
--- a/src/resolve.c
+++ b/src/resolve.c
@@ -19,6 +19,29 @@
#include <string.h>
/*
+** Walk the expression tree pExpr and increase the aggregate function
+** depth (the Expr.op2 field) by N on every TK_AGG_FUNCTION node.
+** This needs to occur when copying a TK_AGG_FUNCTION node from an
+** outer query into an inner subquery.
+**
+** incrAggFunctionDepth(pExpr,n) is the main routine. incrAggDepth(..)
+** is a helper function - a callback for the tree walker.
+*/
+static int incrAggDepth(Walker *pWalker, Expr *pExpr){
+ if( pExpr->op==TK_AGG_FUNCTION ) pExpr->op2 += pWalker->u.i;
+ return WRC_Continue;
+}
+static void incrAggFunctionDepth(Expr *pExpr, int N){
+ if( N>0 ){
+ Walker w;
+ memset(&w, 0, sizeof(w));
+ w.xExprCallback = incrAggDepth;
+ w.u.i = N;
+ sqlite3WalkExpr(&w, pExpr);
+ }
+}
+
+/*
** Turn the pExpr expression into an alias for the iCol-th column of the
** result set in pEList.
**
@@ -44,13 +67,20 @@
** The result of random()%5 in the GROUP BY clause is probably different
** from the result in the result-set. We might fix this someday. Or
** then again, we might not...
+**
+** The nSubquery parameter specifies how many levels of subquery the
+** alias is removed from the original expression. The usually value is
+** zero but it might be more if the alias is contained within a subquery
+** of the original expression. The Expr.op2 field of TK_AGG_FUNCTION
+** structures must be increased by the nSubquery amount.
*/
static void resolveAlias(
Parse *pParse, /* Parsing context */
ExprList *pEList, /* A result set */
int iCol, /* A column in the result set. 0..pEList->nExpr-1 */
Expr *pExpr, /* Transform this into an alias to the result set */
- const char *zType /* "GROUP" or "ORDER" or "" */
+ const char *zType, /* "GROUP" or "ORDER" or "" */
+ int nSubquery /* Number of subqueries that the label is moving */
){
Expr *pOrig; /* The iCol-th column of the result set */
Expr *pDup; /* Copy of pOrig */
@@ -63,6 +93,7 @@
db = pParse->db;
if( pOrig->op!=TK_COLUMN && zType[0]!='G' ){
pDup = sqlite3ExprDup(db, pOrig, 0);
+ incrAggFunctionDepth(pDup, nSubquery);
pDup = sqlite3PExpr(pParse, TK_AS, pDup, 0, 0);
if( pDup==0 ) return;
if( pEList->a[iCol].iAlias==0 ){
@@ -151,9 +182,10 @@
NameContext *pNC, /* The name context used to resolve the name */
Expr *pExpr /* Make this EXPR node point to the selected column */
){
- int i, j; /* Loop counters */
+ int i, j; /* Loop counters */
int cnt = 0; /* Number of matching column names */
int cntTab = 0; /* Number of matching table names */
+ int nSubquery = 0; /* How many levels of subquery */
sqlite3 *db = pParse->db; /* The database connection */
struct SrcList_item *pItem; /* Use for looping over pSrcList items */
struct SrcList_item *pMatch = 0; /* The matching pSrcList item */
@@ -315,7 +347,7 @@
sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs);
return WRC_Abort;
}
- resolveAlias(pParse, pEList, j, pExpr, "");
+ resolveAlias(pParse, pEList, j, pExpr, "", nSubquery);
cnt = 1;
pMatch = 0;
assert( zTab==0 && zDb==0 );
@@ -329,6 +361,7 @@
*/
if( cnt==0 ){
pNC = pNC->pNext;
+ nSubquery++;
}
}
@@ -568,13 +601,19 @@
nId, zId);
pNC->nErr++;
}
- if( is_agg ){
- pExpr->op = TK_AGG_FUNCTION;
- pNC->ncFlags |= NC_HasAgg;
- }
if( is_agg ) pNC->ncFlags &= ~NC_AllowAgg;
sqlite3WalkExprList(pWalker, pList);
- if( is_agg ) pNC->ncFlags |= NC_AllowAgg;
+ if( is_agg ){
+ NameContext *pNC2 = pNC;
+ pExpr->op = TK_AGG_FUNCTION;
+ pExpr->op2 = 0;
+ while( pNC2 && !sqlite3FunctionUsesThisSrc(pExpr, pNC2->pSrcList) ){
+ pExpr->op2++;
+ pNC2 = pNC2->pNext;
+ }
+ if( pNC2 ) pNC2->ncFlags |= NC_HasAgg;
+ pNC->ncFlags |= NC_AllowAgg;
+ }
/* FIX ME: Compute pExpr->affinity based on the expected return
** type of the function
*/
@@ -853,7 +892,7 @@
resolveOutOfRangeError(pParse, zType, i+1, pEList->nExpr);
return 1;
}
- resolveAlias(pParse, pEList, pItem->iOrderByCol-1, pItem->pExpr, zType);
+ resolveAlias(pParse, pEList, pItem->iOrderByCol-1, pItem->pExpr, zType,0);
}
}
return 0;
diff --git a/src/select.c b/src/select.c
index 491356a..a4bb2d4 100644
--- a/src/select.c
+++ b/src/select.c
@@ -3149,7 +3149,7 @@
if( IsVirtual(pTab) ) return 0;
if( pExpr->op!=TK_AGG_FUNCTION ) return 0;
- if( pAggInfo->nFunc==0 ) return 0;
+ if( NEVER(pAggInfo->nFunc==0) ) return 0;
if( (pAggInfo->aFunc[0].pFunc->flags&SQLITE_FUNC_COUNT)==0 ) return 0;
if( pExpr->flags&EP_Distinct ) return 0;
@@ -3521,7 +3521,7 @@
/*
-** This routine sets of a SELECT statement for processing. The
+** This routine sets up a SELECT statement for processing. The
** following is accomplished:
**
** * VDBE Cursor numbers are assigned to all FROM-clause terms.
@@ -3553,7 +3553,8 @@
**
** 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.
+** routine generates code that stores NULLs in all of those memory
+** cells.
*/
static void resetAccumulator(Parse *pParse, AggInfo *pAggInfo){
Vdbe *v = pParse->pVdbe;
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index b3cdb23..443eaa4 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -1690,8 +1690,9 @@
i16 iAgg; /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
i16 iRightJoinTable; /* If EP_FromJoin, the right table of the join */
u8 flags2; /* Second set of flags. EP2_... */
- u8 op2; /* If a TK_REGISTER, the original value of Expr.op */
- /* If TK_COLUMN, the value of p5 for OP_Column */
+ u8 op2; /* TK_REGISTER: original value of Expr.op
+ ** TK_COLUMN: the value of p5 for OP_Column
+ ** TK_AGG_FUNCTION: nesting depth */
AggInfo *pAggInfo; /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
Table *pTab; /* Table for TK_COLUMN expressions. */
#if SQLITE_MAX_EXPR_DEPTH>0
@@ -2498,10 +2499,12 @@
int (*xExprCallback)(Walker*, Expr*); /* Callback for expressions */
int (*xSelectCallback)(Walker*,Select*); /* Callback for SELECTs */
Parse *pParse; /* Parser context. */
+ int walkerDepth; /* Number of subqueries */
union { /* Extra data for callback */
NameContext *pNC; /* Naming context */
int i; /* Integer value */
SrcList *pSrcList; /* FROM clause */
+ struct SrcCount *pSrcCount; /* Counting column references */
} u;
};
@@ -2835,6 +2838,7 @@
int sqlite3ExprListCompare(ExprList*, ExprList*);
void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
+int sqlite3FunctionUsesThisSrc(Expr*, SrcList*);
Vdbe *sqlite3GetVdbe(Parse*);
void sqlite3PrngSaveState(void);
void sqlite3PrngRestoreState(void);
diff --git a/src/walker.c b/src/walker.c
index c95a9c1..eab96ea 100644
--- a/src/walker.c
+++ b/src/walker.c
@@ -125,12 +125,18 @@
int rc;
if( p==0 || pWalker->xSelectCallback==0 ) return WRC_Continue;
rc = WRC_Continue;
- while( p ){
+ pWalker->walkerDepth++;
+ while( p ){
rc = pWalker->xSelectCallback(pWalker, p);
if( rc ) break;
- if( sqlite3WalkSelectExpr(pWalker, p) ) return WRC_Abort;
- if( sqlite3WalkSelectFrom(pWalker, p) ) return WRC_Abort;
+ if( sqlite3WalkSelectExpr(pWalker, p)
+ || sqlite3WalkSelectFrom(pWalker, p)
+ ){
+ pWalker->walkerDepth--;
+ return WRC_Abort;
+ }
p = p->pPrior;
}
+ pWalker->walkerDepth--;
return rc & WRC_Abort;
}