Only allow NULL in the prpoer places.

diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index d412e4db23e3896a150596968d98c4b81f92fff7..af0e6c5c67e7c86ffd764df4d8eeacdda6e0ca60 100644 (file)
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 1.25 1997/01/16 14:56:05 momjian Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 1.26 1997/02/13 15:40:03 momjian Exp $
  *
  * HISTORY
  *    AUTHOR       DATE        MAJOR EVENT
@@ -149,7 +149,8 @@ static Node *makeA_Expr(int oper, char *opname, Node *lexpr, Node *rexpr);
 %type  columnDef
 %type  def_elem
 %type    def_arg, columnElem, where_clause, 
-       a_expr, AexprConst, in_expr_nodes, not_in_expr_nodes,
+       a_expr, a_expr_or_null, AexprConst,
+       in_expr_nodes, not_in_expr_nodes,
        having_clause
 %type   NumConst
 %type    event_object, attr
@@ -1751,6 +1752,15 @@ Typename:  typname opt_array_bounds
  *
  *****************************************************************************/
 
+a_expr_or_null: a_expr
+       { $$ = $1;}
+   | Pnull
+       {   
+           A_Const *n = makeNode(A_Const);
+           n->val.type = T_Null;
+           $$ = (Node *)n;
+       }
+       
 a_expr:  attr opt_indirection
        {
            $1->indirection = $2;
@@ -1800,7 +1810,7 @@ a_expr:  attr opt_indirection
            }
            $$ = (Node *)$2;
        }
-   | '(' a_expr ')'
+   | '(' a_expr_or_null ')'
        {   $$ = $2; }
    | a_expr Op a_expr
        {   $$ = makeA_Expr(OP, $2, $1, $3); }
@@ -1892,9 +1902,9 @@ opt_indirection:  '[' a_expr ']' opt_indirection
        {   $$ = NIL; }
    ;
    
-expr_list: a_expr
+expr_list: a_expr_or_null
        { $$ = lcons($1, NIL); }
-   |  expr_list ',' a_expr
+   |  expr_list ',' a_expr_or_null
        { $$ = lappend($1, $3); }
    ;
 
@@ -1966,7 +1976,7 @@ res_target_list:  res_target_list ',' res_target_el
        }
    ;
 
-res_target_el: Id opt_indirection '=' a_expr
+res_target_el: Id opt_indirection '=' a_expr_or_null
        {
            $$ = makeNode(ResTarget);
            $$->name = $1;
@@ -2014,7 +2024,7 @@ res_target_el2: a_expr AS Id
            $$->indirection = NULL;
            $$->val = (Node *)$1;
        }
-   | a_expr
+   | a_expr_or_null
        {
            $$ = makeNode(ResTarget);
            $$->name = NULL;
@@ -2108,12 +2118,6 @@ AexprConst:  Iconst
        }
    | ParamNo
        {   $$ = (Node *)$1;  }
-   | Pnull     
-       {   
-           A_Const *n = makeNode(A_Const);
-           n->val.type = T_Null;
-           $$ = (Node *)n;
-       }
    ;
 
 ParamNo:  PARAM