gram.y - Mailing list pgsql-hackers

Hi all,

I'm trying to make parser recognize SELECTs between parenthesis.
I need to do this work to have m$access working with PostgreSQL.
The micro$oft access jet (great wisdom) translates the UNIONs as:
(SELECT ...) UNION (SELECT ...)
To have PostgreSQL understand this syntax I edited gram.y
and I modified the "SelectStmt:" and the "SubUnion:" as:

SelectStmt: opt_left_paren SELECT                          opt_unique                          res_target_list2
                result                          from_clause                          where_clause
  group_clause                          having_clause           opt_right_paren                          union_clause
                      sort_clause                               {                                       SelectStmt *n
=makeNode(SelectStmt);                                       n->unique       = $3;
n->targetList   = $4;                                       n->into         = $5;
n->fromClause  = $6;                                       n->whereClause  = $7;
n->groupClause = $8;                                       n->havingClause = $9;
n->unionClause = $11;                                       n->sortClause   = $12;
$$ = (Node *)n;                               }               ;
 

SubUnion: opt_left_paren SELECT opt_unique res_target_list2                        from_clause where_clause
          group_clause having_clause opt_right_paren                               {
  SelectStmt *n   = makeNode(SelectStmt);                                       n->unique       = $3;
                   n->unionall     = FALSE;                                       n->targetList   = $4;
                     n->fromClause   = $5;                                       n->whereClause  = $6;
                    n->groupClause  = $7;                                       n->havingClause = $8;
                   $$ = (Node *)n;                               }               ;
 


and now with these changes I can specify SELECTs inside () and
without parenthesis as before, I tried also subselects and seems that
all works well...but when I tried a select with a function which contains
parenthesis, like SUM(), VERSION() for example, then it doesn't work anymore.
I'm not very good programing in C.
Is there anybody that can help me with this question ?
Any help would be very appreciated.

EXAMPLES:

(select (2-3)*3);
?column?
--------     -3
(1 row)

(select (132-3)*3)  union all ( select ((983+1)/2) );
?column?
--------    387    492
(2 rows)

select (132-3)*3  union all  select ((983+1)/2);
?column?
--------    387    492
(2 rows)

select ename from emp where ename in (    select ename from emp where ename like 'K%'    );
ename
-----
KING
(1 row)

select version();
ERROR:  parser: parse error at or near "("

-Jose'-