David Pradier <dpradier(at)apartia(dot)fr> writes:
> One can access the columns of the main query from the subquery,
> therefore in my own query the column "id_compte" is found,
> therefore there is no error message.
> Doesn't this count as a bug ?
No; it's required behavior per the SQL specification. The spec doesn't
restrict the sub-query to reference outer columns in only some places;
it can use them anywhere.
(If you think that's weird, you should try putting the outer reference
in an aggregate function ... it then counts as an aggregate of the outer
query, not the inner. Also per spec.)
regards, tom lane