Come to think of it, functions in FROM have the same syntactic restriction

as CREATE INDEX did, and can be fixed the same way, for another small
improvement in usability and reduction in grammar size.

diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index c54197ffb7e04811ae50b46b5b0b790e76a882fc..8f1b393d29a084f8e2f5221f37fba14874532969 100644 (file)
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.476 2004/09/29 23:39:20 tgl Exp $
+ *   $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.477 2004/09/30 00:24:20 tgl Exp $
  *
  * HISTORY
  *   AUTHOR            DATE            MAJOR EVENT
@@ -5368,24 +5368,7 @@ relation_expr:
        ;
 
 
-func_table: func_name '(' ')'
-               {
-                   FuncCall *n = makeNode(FuncCall);
-                   n->funcname = $1;
-                   n->args = NIL;
-                   n->agg_star = FALSE;
-                   n->agg_distinct = FALSE;
-                   $$ = (Node *)n;
-               }
-           | func_name '(' expr_list ')'
-               {
-                   FuncCall *n = makeNode(FuncCall);
-                   n->funcname = $1;
-                   n->args = $3;
-                   n->agg_star = FALSE;
-                   n->agg_distinct = FALSE;
-                   $$ = (Node *)n;
-               }
+func_table: func_expr                              { $$ = $1; }
        ;
 
 
@@ -6978,6 +6961,16 @@ func_expr:   func_name '(' ')'
                    n->agg_distinct = FALSE;
                    $$ = (Node *)n;
                }
+           | NULLIF '(' a_expr ',' a_expr ')'
+               {
+                   $$ = (Node *) makeSimpleA_Expr(AEXPR_NULLIF, "=", $3, $5);
+               }
+           | COALESCE '(' expr_list ')'
+               {
+                   CoalesceExpr *c = makeNode(CoalesceExpr);
+                   c->args = $3;
+                   $$ = (Node *)c;
+               }
        ;
 
 /*
@@ -7206,24 +7199,12 @@ in_expr:    select_with_parens
            | '(' expr_list ')'                     { $$ = (Node *)$2; }
        ;
 
-/* Case clause
+/*
  * Define SQL92-style case clause.
- * Allow all four forms described in the standard:
  * - Full specification
  * CASE WHEN a = b THEN c ... ELSE d END
  * - Implicit argument
  * CASE a WHEN b THEN c ... ELSE d END
- * - Conditional NULL
- * NULLIF(x,y)
- * same as CASE WHEN x = y THEN NULL ELSE x END
- * - Conditional substitution from list, use first non-null argument
- * COALESCE(a,b,...)
- * same as CASE WHEN a IS NOT NULL THEN a WHEN b IS NOT NULL THEN b ... END
- * - thomas 1998-11-09
- *
- * NULLIF and COALESCE have become first class nodes to
- * prevent double evaluation of arguments.
- * - Kris Jurka 2003-02-11
  */
 case_expr: CASE case_arg when_clause_list case_default END_P
                {
@@ -7234,16 +7215,6 @@ case_expr:   CASE case_arg when_clause_list case_default END_P
                    c->defresult = (Expr *) $4;
                    $$ = (Node *)c;
                }
-           | NULLIF '(' a_expr ',' a_expr ')'
-               {
-                   $$ = (Node *) makeSimpleA_Expr(AEXPR_NULLIF, "=", $3, $5);
-               }
-           | COALESCE '(' expr_list ')'
-               {
-                   CoalesceExpr *c = makeNode(CoalesceExpr);
-                   c->args = $3;
-                   $$ = (Node *)c;
-               }
        ;
 
 when_clause_list:

diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c
index a0dd961363db7b4f3f5aa5c277403eb5df6cc875..af3cbffa7007c35ecd4a4a33673a8581bba8a5e0 100644 (file)
--- a/src/backend/parser/parse_clause.c
+++ b/src/backend/parser/parse_clause.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/parser/parse_clause.c,v 1.136 2004/08/29 05:06:44 momjian Exp $
+ *   $PostgreSQL: pgsql/src/backend/parser/parse_clause.c,v 1.137 2004/09/30 00:24:21 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -497,12 +497,16 @@ transformRangeFunction(ParseState *pstate, RangeFunction *r)
    RangeTblEntry *rte;
    RangeTblRef *rtr;
 
-   /* Get function name for possible use as alias */
-   Assert(IsA(r->funccallnode, FuncCall));
-   funcname = strVal(llast(((FuncCall *) r->funccallnode)->funcname));
+   /*
+    * Get function name for possible use as alias.  We use the same
+    * transformation rules as for a SELECT output expression.  For a
+    * FuncCall node, the result will be the function name, but it is
+    * possible for the grammar to hand back other node types.
+    */
+   funcname = FigureColname(r->funccallnode);
 
    /*
-    * Transform the raw FuncCall node.
+    * Transform the raw expression.
     */
    funcexpr = transformExpr(pstate, r->funccallnode);
 

diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 35375c39ac37f9c4e70341000690fd0d137102dc..b130a842aff00db3afa1e9e16002f94d360a0bbb 100644 (file)
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/parser/parse_target.c,v 1.125 2004/08/29 05:06:44 momjian Exp $
+ *   $PostgreSQL: pgsql/src/backend/parser/parse_target.c,v 1.126 2004/09/30 00:24:21 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -41,7 +41,6 @@ static Node *transformAssignmentIndirection(ParseState *pstate,
 static List *ExpandColumnRefStar(ParseState *pstate, ColumnRef *cref);
 static List *ExpandAllTables(ParseState *pstate);
 static List *ExpandIndirectionStar(ParseState *pstate, A_Indirection *ind);
-static char *FigureColname(Node *node);
 static int FigureColnameInternal(Node *node, char **name);
 
 
@@ -893,7 +892,7 @@ ExpandIndirectionStar(ParseState *pstate, A_Indirection *ind)
  * Note that the argument is the *untransformed* parse tree for the target
  * item.  This is a shade easier to work with than the transformed tree.
  */
-static char *
+char *
 FigureColname(Node *node)
 {
    char       *name = NULL;

diff --git a/src/include/parser/parse_target.h b/src/include/parser/parse_target.h
index e1cd2dcca55bd5b376caeb53208fc70a1ec58a6f..71dfd35c1d82f187a2ba17064f62ee3536f4733b 100644 (file)
--- a/src/include/parser/parse_target.h
+++ b/src/include/parser/parse_target.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2004, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/parser/parse_target.h,v 1.33 2004/08/29 04:13:09 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/parser/parse_target.h,v 1.34 2004/09/30 00:24:27 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -27,5 +27,6 @@ extern void updateTargetListEntry(ParseState *pstate, TargetEntry *tle,
                      List *indirection);
 extern List *checkInsertTargets(ParseState *pstate, List *cols,
                   List **attrnos);
+extern char *FigureColname(Node *node);
 
 #endif   /* PARSE_TARGET_H */