Re: help on a query - Mailing list pgsql-sql

On Friday 08 October 2004 07:10, Thomas F.O'Connell wrote:
> A query that should get the job done is:
>
> SELECT registration_id
> FROM registrations r
> WHERE NOT EXISTS (
>     SELECT 1
>     FROM receipts
>     WHERE registration_id = r.registration_id
> );

Don't, PLEASE, don't !!!

drive this way :

SELECT r.registration_idFROM registrations AS r
LEFT OUTER JOIN receipts AS recON rec.registration_id = r.registration_id
WHERE rec.registration_id IS NULL;