NOT IN queries - Mailing list pgsql-general

From Nic Ferrier
Subject NOT IN queries
Date
Msg-id 87vgbbo1l7.fsf@pooh-sticks-bridge.tapsellferrier.co.uk
Whole thread Raw
In response to PostgreSQL v7.2 Final Release  ("Marc G. Fournier" <scrappy@postgresql.org>)
Responses Re: NOT IN queries
Re: NOT IN queries
List pgsql-general
The following seems to be a bug in 7.2 (and in 7.1.2) I'm pretty sure
it worked before, certainly it's something I do a lot (but postgresql
isn't the only database I use).

The bug concerns a NOT IN on a list generated by a select. If you
have two tables thus:


  create table t1 (id integer, name varchar(20), t2_id integer);
  insert into t1 (id, name, t2_id) values (1, 'nic', 2);
  insert into t1 (id, name, t2_id) values (2, 'jim', NULL);

  create table t2 (id integer, name varchar(20));
  insert into t1 (id, name, t2_id) values (1, 'ferrier');
  insert into t1 (id, name, t2_id) values (2, 'broadbent');

And now do this query:

  select * from t2 where id not in (select t2_id from t1);

then I get a NULL response (ie: no rows returned).

What I SHOULD get is the row from t2 with id == 2;


Nic Ferrier

pgsql-general by date:

Previous
From: Fran Fabrizio
Date:
Subject: PostgreSQL success stories
Next
From: Doug McNaught
Date:
Subject: Re: NOT IN queries