Re: NOT IN queries

Nic Ferrier <nferrier@tapsellferrier.co.uk> writes:

>   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).

Well, you never inserted any rows into t2, so that makes sense.

-Doug
--
Doug McNaught       Wireboard Industries      http://www.wireboard.com/

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