Make GROUP BY work with aliases, ORDER BY with column numbers

src/backend/parser/analyze.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.18 1996/11/30 18:06:20 momjian Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.19 1996/12/17 01:53:26 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -63,7 +63,8 @@ static TargetEntry *make_targetlist_expr(ParseState *pstate,
 					 char *colname, Node *expr,
 					 List *arrayRef);
 static Node *transformWhereClause(ParseState *pstate, Node *a_expr);
-static List *transformGroupClause(ParseState *pstate, List *grouplist);
+static List *transformGroupClause(ParseState *pstate, List *grouplist,
+							List *targetlist);
 static List *transformSortClause(ParseState *pstate,
 				 List *orderlist, List *targetlist,
 				 char* uniqueFlag);
@@ -422,13 +423,14 @@ transformSelectStmt(ParseState *pstate, RetrieveStmt *stmt)
 
     /* fix order clause */
     qry->sortClause = transformSortClause(pstate,
-					  stmt->orderClause,
+					  stmt->sortClause,
 					  qry->targetList,
 					  qry->uniqueFlag);
 
     /* fix group by clause */
     qry->groupClause = transformGroupClause(pstate,
-					    stmt->groupClause);
+					  stmt->groupClause,
+					  qry->targetList);
     qry->rtable = pstate->p_rtable;
 
     if (pstate->p_numAgg > 0)
@@ -505,12 +507,13 @@ transformCursorStmt(ParseState *pstate, CursorStmt *stmt)
 
     /* fix order clause */
     qry->sortClause = transformSortClause(pstate,
-					  stmt->orderClause,
+					  stmt->sortClause,
 					  qry->targetList,
 					  qry->uniqueFlag);
     /* fix group by clause */
     qry->groupClause = transformGroupClause(pstate,
-                                          stmt->groupClause);
+                                          stmt->groupClause,
+					  qry->targetList);
 
     qry->rtable = pstate->p_rtable;
 
@@ -1426,19 +1429,21 @@ transformWhereClause(ParseState *pstate, Node *a_expr)
  *****************************************************************************/
 
 /*
- *  find_tl_elt -
+ *  find_targetlist_entry -
  *    returns the Resdom in the target list matching the specified varname
  *    and range
  *
  */
-static Resdom *
-find_tl_elt(ParseState *pstate, char *refname, char *colname, List *tlist)
+static TargetEntry *
+find_targetlist_entry(ParseState *pstate, SortGroupBy *sortgroupby, List *tlist)
 {
     List *i;
-    int real_rtable_pos = 0;
-
-    if(refname)
-	real_rtable_pos = refnameRangeTablePosn(pstate->p_rtable, refname);
+    int real_rtable_pos = 0, target_pos = 0;
+    TargetEntry *target_result = NULL;
+    
+    if(sortgroupby->range)
+	real_rtable_pos = refnameRangeTablePosn(pstate->p_rtable,
+							sortgroupby->range);
 
     foreach(i, tlist) {
 	TargetEntry *target = (TargetEntry *)lfirst(i);
@@ -1447,17 +1452,30 @@ find_tl_elt(ParseState *pstate, char *refname, char *colname, List *tlist)
 	char *resname = resnode->resname;
 	int test_rtable_pos = var->varno;
 
-	if (!strcmp(resname, colname)) {
-	    if(refname) {
-		if(real_rtable_pos == test_rtable_pos) {
-		    return (resnode);
-		}
-	    } else {
-		return (resnode);
+	if (!sortgroupby->name) {
+	    if (sortgroupby->resno == ++target_pos) {
+	    	target_result = target;
+	    	break;
+	    }
+	}
+	else {
+	    if (!strcmp(resname, sortgroupby->name)) {
+	        if(sortgroupby->range) {
+	    	    if(real_rtable_pos == test_rtable_pos) {
+		        if (target_result != NULL)
+		  	    elog(WARN, "Order/Group By %s is ambiguous", sortgroupby->name);
+			else    target_result = target;
+		    }
+		}			
+	    	else {
+		    if (target_result != NULL)
+		    	elog(WARN, "Order/Group By %s is ambiguous", sortgroupby->name);
+ 	            else	target_result = target;
+	    	}
 	    }
 	}
     }
-    return ((Resdom *)NULL);
+    return target_result;
 }
 
 static Oid
@@ -1478,22 +1496,27 @@ any_ordering_op(int restype)
  *
  */
 static List *
-transformGroupClause(ParseState *pstate, List *grouplist)
+transformGroupClause(ParseState *pstate, List *grouplist, List *targetlist)
 {
     List *glist = NIL, *gl = NIL;
 
     while (grouplist != NIL) {
 	GroupClause *grpcl = makeNode(GroupClause);
-	Var *groupAttr = (Var*)transformExpr(pstate, (Node*)lfirst(grouplist));
+	TargetEntry *restarget;
 
-	if (nodeTag(groupAttr) != T_Var) {
-	    elog(WARN, "parser: can only specify attribute in group by");
-	}
-	grpcl->grpAttr = groupAttr;
-	grpcl->grpOpoid = any_ordering_op(groupAttr->vartype);
-	if (glist == NIL) {
+	restarget = find_targetlist_entry(pstate, lfirst(grouplist), targetlist);
+
+	if (restarget == NULL)
+	    elog(WARN,"The field being grouped by must appear in the target list");
+        if (nodeTag(restarget->expr) != T_Var) {
+            elog(WARN, "parser: can only specify attribute in group by");
+        }
+
+	grpcl->grpAttr = (Var *)restarget->expr;
+ 	grpcl->grpOpoid = any_ordering_op(grpcl->grpAttr->vartype);
+	if (glist == NIL)
 	    gl = glist = lcons(grpcl, NIL);
-	} else {
+	else {
 	    lnext(gl) = lcons(grpcl, NIL);
 	    gl = lnext(gl);
 	}
@@ -1517,15 +1540,16 @@ transformSortClause(ParseState *pstate,
     List *s = NIL, *i;
 
     while(orderlist != NIL) {
-	SortBy *sortby = lfirst(orderlist);
+	SortGroupBy *sortby = lfirst(orderlist);
 	SortClause *sortcl = makeNode(SortClause);
+	TargetEntry *restarget;
 	Resdom *resdom;
-	
-	resdom = find_tl_elt(pstate, sortby->range, sortby->name, targetlist);
-	if (resdom == NULL)
-	    elog(WARN,"The field being sorted by must appear in the target list");
-	
-	sortcl->resdom = resdom;
+
+	restarget = find_targetlist_entry(pstate, sortby, targetlist);
+	if (restarget == NULL)
+	    elog(WARN,"The field being ordered by must appear in the target list");
+
+	sortcl->resdom = resdom = restarget->resdom;
 	sortcl->opoid = oprid(oper(sortby->useOp,
 				   resdom->restype,
 				   resdom->restype));

src/backend/parser/gram.y

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 1.21 1996/12/11 22:55:53 momjian Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 1.22 1996/12/17 01:53:29 momjian Exp $
  *
  * HISTORY
  *    AUTHOR		DATE		MAJOR EVENT
@@ -82,7 +82,7 @@ static Node *makeA_Expr(int oper, char *opname, Node *lexpr, Node *rexpr);
     TypeName		*typnam;
     DefElem		*defelt;
     ParamString		*param;
-    SortBy		*sortby;
+    SortGroupBy		*sortgroupby;
     IndexElem		*ielem;
     RangeVar		*range;
     RelExpr		*relexp;
@@ -146,10 +146,11 @@ static Node *makeA_Expr(int oper, char *opname, Node *lexpr, Node *rexpr);
 %type <defelt>	def_elem
 %type <node>	def_arg, columnElem, where_clause, 
 		a_expr, AexprConst, in_expr_nodes, not_in_expr_nodes,
-		having_clause, groupby
+		having_clause
 %type <value>	NumConst
 %type <attr>	event_object, attr
-%type <sortby>	sortby
+%type <sortgroupby>	groupby
+%type <sortgroupby>	sortby
 %type <ielem>	index_elem, func_index
 %type <range>	from_val
 %type <relexp>	relation_expr
@@ -1359,7 +1360,7 @@ CursorStmt:  DECLARE name opt_binary CURSOR FOR
 		    n->fromClause = $9;
 		    n->whereClause = $10;
 		    n->groupClause = $11;
-		    n->orderClause = $12;
+		    n->sortClause = $12;
 		    $$ = (Node *)n;
 		}
 	;
@@ -1385,7 +1386,7 @@ RetrieveStmt:  SELECT opt_unique res_target_list2
 		    n->whereClause = $6;
 		    n->groupClause = $7;
 		    n->havingClause = $8;
-		    n->orderClause = $9;
+		    n->sortClause = $9;
 		    $$ = (Node *)n;
 		}
 	;
@@ -1413,22 +1414,28 @@ sortby_list:  sortby
 
 sortby:  Id OptUseOp
 		{ 
-		    $$ = makeNode(SortBy);
+		    $$ = makeNode(SortGroupBy);
+		    $$->resno = 0;
 		    $$->range = NULL;
 		    $$->name = $1;
 		    $$->useOp = $2;
 		}
 	| Id '.' Id OptUseOp
 		{
-		    $$ = makeNode(SortBy);
+		    $$ = makeNode(SortGroupBy);
+		    $$->resno = 0;
 		    $$->range = $1;
 		    $$->name = $3;
 		    $$->useOp = $4;
 		}
-        | /*EMPTY*/
-                { 
-                  yyerror("parse error: use 'order by attribute_name'");
-                }
+	| Iconst OptUseOp
+		{
+		    $$ = makeNode(SortGroupBy);
+		    $$->resno = $1;
+		    $$->range = NULL;
+		    $$->name = NULL;
+		    $$->useOp = $2;
+		}
 	;
 
 OptUseOp:  USING Op				{ $$ = $2; }
@@ -1509,16 +1516,29 @@ groupby_list: groupby				{ $$ = lcons($1, NIL); }
 	| groupby_list ',' groupby		{ $$ = lappend($1, $3); }
 	;
 
-groupby: Id					
-		{ 
-		   Ident *n = makeNode(Ident);
-		   n->name = $1;
-		   n->indirection = NULL;
-		   $$ = (Node*)n;
+groupby:  Id
+		{
+		    $$ = makeNode(SortGroupBy);
+		    $$->resno = 0;
+		    $$->range = NULL;
+		    $$->name = $1;
+		    $$->useOp = NULL;
 		}
-	| attr
+	| Id '.' Id
 		{
-		   $$ = (Node*)$1;
+		    $$ = makeNode(SortGroupBy);
+		    $$->resno = 0;
+		    $$->range = $1;
+		    $$->name = $3;
+		    $$->useOp = NULL;
+		}
+	| Iconst
+		{
+		    $$ = makeNode(SortGroupBy);
+		    $$->resno = $1;
+		    $$->range = NULL;
+		    $$->name = NULL;
+		    $$->useOp = NULL;
 		}
 	;
 

src/include/nodes/nodes.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: nodes.h,v 1.3 1996/11/03 12:12:52 scrappy Exp $
+ * $Id: nodes.h,v 1.4 1996/12/17 01:53:40 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -190,7 +190,7 @@ typedef enum NodeTag {
     T_ParamString,
     T_TimeRange,
     T_RelExpr,
-    T_SortBy,
+    T_SortGroupBy,
     T_RangeVar,
     T_TypeName,
     T_IndexElem,

src/include/nodes/parsenodes.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: parsenodes.h,v 1.7 1996/11/13 20:56:15 scrappy Exp $
+ * $Id: parsenodes.h,v 1.8 1996/12/17 01:53:43 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -463,7 +463,7 @@ typedef struct CursorStmt {
     List		*fromClause;	/* the from clause */
     Node		*whereClause;	/* qualifications */
     List              *groupClause;   /* group by clause */
-    List		*orderClause;	/* sort clause (a list of SortBy's) */
+    List		*sortClause;	/* sort clause (a list of SortGroupBy's) */
 } CursorStmt;    
 
 /* ----------------------
@@ -480,7 +480,7 @@ typedef struct RetrieveStmt {
     Node		*whereClause;	/* qualifications */
     List		*groupClause;	/* group by clause */
     Node		*havingClause;	/* having conditional-expression */
-    List		*orderClause;	/* sort clause (a list of SortBy's) */
+    List		*sortClause;	/* sort clause (a list of SortGroupBy's) */
 } RetrieveStmt;    
 
 
@@ -627,14 +627,15 @@ typedef struct RelExpr {
 } RelExpr;
 
 /*
- * Sortby - for order by clause
+ * SortGroupBy - for order by clause
  */
-typedef struct SortBy {
+typedef struct SortGroupBy {
     NodeTag		type;
+    int			resno;		/* target number */
     char                *range;
     char		*name;		/* name of column to sort on */
     char		*useOp;		/* operator to use */
-} SortBy;
+} SortGroupBy;
 
 /*
  * RangeVar - range variable, used in from clauses