"Pascal Tufenkji" <[EMAIL PROTECTED]> writes: > I understand the fact that "the inner query is executed before the outer > query and the inner query doesn't even know about the outer query." > > But why the following query can be executed, although the inner query is > using the outer query. > > Aren't we here using the same concept ?
It's not that inner queries can't refer to outer queries. When they do it's called a "correlated subquery" and it has to be executed once for every row of the outer query. It's that queries on one side of a join can't refer to tables on the other side of the join. -- Gregory Stark EnterpriseDB http://www.enterprisedb.com Ask me about EnterpriseDB's On-Demand Production Tuning -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
