> Now, what I want is to select the b_date which has the minimum "id" and
> active=t.
>
> A normal query would be :
> SELECT b_date,min(id) FROM test WHERE active='t' GROUP BY id LIMIT 1
>
> However, I only want to select b_date. So, if I perform the following
> query, I get the following error:
>
> devrim=# SELECT b_date FROM test WHERE active='t' AND id=min(id) LIMIT 1;
> ERROR: Aggregates not allowed in WHERE clause
Use a subselect (and don't compare to 't' if it's a boolean field...)
SELECT b_date FROM test WHERE active AND id=(SELECT min(id) FROM test) LIMIT
1;
Chris