Re: help on a query

Just curious, what is wrong with the first way of coding the solution?
------------------( Forwarded letter 1 follows )---------------------
Date: Fri, 8 Oct 2004 08:44:23 +0400
To: Thomas.F.O'Connell[tfo](at)sitening(dot)com(dot)comp, mmurrain(at)dbdes(dot)com(dot)comp
Cc: pgsql-sql(at)postgresql(dot)org(dot)comp
From: sad(at)bankir(dot)ru(dot)comp
Sender: pgsql-sql-owner+m19150(at)postgresql(dot)org(dot)comp
Subject: Re: [SQL] help on a query

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_id
FROM registrations AS r
LEFT OUTER JOIN receipts AS rec
ON rec.registration_id = r.registration_id
WHERE rec.registration_id IS NULL;

---------------------------(end of broadcast)---------------------------
TIP 6: Have you searched our list archives?

http://archives.postgresql.org