Re: BUG #4742: wrong resultset instead of syntax error

Slava Moudry wrote:
> I believe this is a parser error, it should fail rather than return all rows
> from keyword since there is no keyword_id in carrier table. The same can be
> illustrated with any other tables:
>
> smslocate_edw=# select count(*) from keyword where keyword_id in (select
> keyword_id from carrier)

It's not a bug, although I admit I've done the same mistake myself many
times. keyword_id refers to keyword.keyword_id from the outer query in
this case. It makes sense if you think of a more complex query like:

select count(*) from keyword where keyword_ratio > (select keyword_id /
carrier_id from carrier)

If keyword_id wasn't allowed in the subquery, it would be impossible to
write more complex queries like that.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com