"Harry Jackson" <harryjackson@xxxxxxxxx> writes: > If I made a mistake and changed the "id" column to "user_id" then from > some the statement executes. > =# delete from map_users_roles where user_id = (select user_id from > users WHERE username = 'blah'); This is a standard "outer reference" construction, ie, user_id refers to the field exposed in the outer-level query if there's no match in the inner query. Possibly the SQL spec authors should have made it a little harder to invoke an outer reference, but they didn't. regards, tom lane
