Handle multiple window-functions in a single query.

FossilOrigin-Name: 35af0b750e70dcf0f343b115f4bbd0860a7e8064be204d4dfba1a43c22ff07b1

2 files changed, 34 insertions, 29 deletions

diff --git a/src/expr.c b/src/expr.c
index a1407a85f..faaca6c86 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -772,6 +772,7 @@ Expr *sqlite3ExprAlloc(
     memset(pNew, 0, sizeof(Expr));
     pNew->op = (u8)op;
     pNew->iAgg = -1;
+    pNew->pWin = 0;
     if( pToken ){
       if( nExtra==0 ){
         pNew->flags |= EP_IntValue|EP_Leaf;
@@ -861,6 +862,7 @@ Expr *sqlite3PExpr(
       memset(p, 0, sizeof(Expr));
       p->op = op & TKFLG_MASK;
       p->iAgg = -1;
+      p->pWin = 0;
     }
     sqlite3ExprAttachSubtrees(pParse->db, p, pLeft, pRight);
   }
@@ -1180,6 +1182,24 @@ static int dupedExprSize(Expr *p, int flags){
   return nByte;
 }
 
+static Window *winDup(sqlite3 *db, Window *p){
+  Window *pNew = 0;
+  if( p ){
+    pNew = sqlite3DbMallocZero(db, sizeof(Window));
+    if( pNew ){
+      pNew->pFilter = sqlite3ExprDup(db, p->pFilter, 0);
+      pNew->pPartition = sqlite3ExprListDup(db, p->pPartition, 0);
+      pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, 0);
+      pNew->eType = p->eType;
+      pNew->eEnd = p->eEnd;
+      pNew->eStart = p->eStart;
+      pNew->pStart = sqlite3ExprDup(db, pNew->pStart, 0);
+      pNew->pEnd = sqlite3ExprDup(db, pNew->pEnd, 0);
+    }
+  }
+  return pNew;
+}
+
 /*
 ** This function is similar to sqlite3ExprDup(), except that if pzBuffer 
 ** is not NULL then *pzBuffer is assumed to point to a buffer large enough 
@@ -1266,6 +1286,7 @@ static Expr *exprDup(sqlite3 *db, Expr *p, int dupFlags, u8 **pzBuffer){
         *pzBuffer = zAlloc;
       }
     }else{
+      pNew->pWin = winDup(db, p->pWin);
       if( !ExprHasProperty(p, EP_TokenOnly|EP_Leaf) ){
         if( pNew->op==TK_SELECT_COLUMN ){
           pNew->pLeft = p->pLeft;
@@ -1308,24 +1329,6 @@ static With *withDup(sqlite3 *db, With *p){
 # define withDup(x,y) 0
 #endif
 
-static Window *winDup(sqlite3 *db, Window *p){
-  Window *pNew = 0;
-  if( p ){
-    pNew = sqlite3DbMallocZero(db, sizeof(Window));
-    if( pNew ){
-      pNew->pFilter = sqlite3ExprDup(db, p->pFilter, 0);
-      pNew->pPartition = sqlite3ExprListDup(db, p->pPartition, 0);
-      pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy, 0);
-      pNew->eType = p->eType;
-      pNew->eEnd = p->eEnd;
-      pNew->eStart = p->eStart;
-      pNew->pStart = sqlite3ExprDup(db, pNew->pStart, 0);
-      pNew->pEnd = sqlite3ExprDup(db, pNew->pEnd, 0);
-    }
-  }
-  return pNew;
-}
-
 /*
 ** The following group of routines make deep copies of expressions,
 ** expression lists, ID lists, and select statements.  The copies can
@@ -1490,7 +1493,7 @@ Select *sqlite3SelectDup(sqlite3 *db, Select *pDup, int flags){
     pNew->addrOpenEphm[1] = -1;
     pNew->nSelectRow = p->nSelectRow;
     pNew->pWith = withDup(db, p->pWith);
-    pNew->pWin = winDup(db, p->pWin);
+    pNew->pWin = 0;
     sqlite3SelectSetName(pNew, p->zSelName);
     *pp = pNew;
     pp = &pNew->pPrior;
diff --git a/src/select.c b/src/select.c
index 2b5a3dc54..93e55b680 100644
--- a/src/select.c
+++ b/src/select.c
@@ -5418,6 +5418,17 @@ static int selectWindowRewriteExprCb(Walker *pWalker, Expr *pExpr){
   int rc = WRC_Continue;
 
   switch( pExpr->op ){
+
+    case TK_FUNCTION:
+      if( pExpr->pWin==0 ){
+        break;
+      }else if( pExpr->pWin==p->pWin ){
+        rc = WRC_Prune;
+        pExpr->pWin->pOwner = pExpr;
+        break;
+      }
+      /* Fall through.  */
+
     case TK_COLUMN: {
       Expr *pDup = sqlite3ExprDup(pParse->db, pExpr, 0);
       p->pSub = sqlite3ExprListAppend(pParse, p->pSub, pDup);
@@ -5436,13 +5447,6 @@ static int selectWindowRewriteExprCb(Walker *pWalker, Expr *pExpr){
       break;
     }
 
-    case TK_FUNCTION:
-      if( pExpr->pWin ){
-        rc = WRC_Prune;
-        pExpr->pWin->pOwner = pExpr;
-      }
-      break;
-
     default: /* no-op */
       break;
   }
@@ -5530,9 +5534,6 @@ static int selectWindowRewrite(Parse *pParse, Select *p){
     ExprList *pSublist = 0;       /* Expression list for sub-query */
     Window *pWin = p->pWin;
 
-    /* TODO: This is of course temporary requirements */
-    assert( pWin->pNextWin==0 );
-
     p->pSrc = 0;
     p->pWhere = 0;
     p->pGroupBy = 0;
@@ -5581,6 +5582,7 @@ static int selectWindowRewrite(Parse *pParse, Select *p){
       }else{
         pSub->selFlags |= SF_Expanded;
       }
+      pWin->pNextWin = 0;
     }
 
 #if SELECTTRACE_ENABLED