A query that should get the job done is:
SELECT registration_id
FROM registrations r
WHERE NOT EXISTS (SELECT 1FROM receiptsWHERE registration_id = r.registration_id
);
There might be a more efficient version with JOINs that don't require a
subquery, but this should get you started.
-tfo
On Oct 7, 2004, at 10:03 PM, Michelle Murrain wrote:
> Hi all,
>
> This is one of those things I know I should know, but it's not coming
> to me. It's probably really simple.
>
> I have two related tables, registrations and receipts, related by the
> field registration_id.
>
> So registrations looks kinda like:
>
> registration_id bigint (primary key)
> foo varchar(10)
> bar varchar(20)
>
> and receipts looks like:
>
> receipt_id bigint (primary key)
> registration_id bigint (foreign key)
> amount float
> baz varchar(10)
>
> If someone has paid, there is a row in the receipts table for that
> registration ID#.
>
> I need to find a list of the registration IDs that *don't* have an
> entry in the receipts table.
>
> Thanks in advance!!!
> --
> .Michelle
>
> --------------------------
> Michelle Murrain
> mmurrain at dbdes dot com
> 413-222-6350 ph
> 617-889-0929 ph
> 952-674-7253 fax <--- new
> Page: pageme@murrain.net
> AIM:pearlbear0 ICQ:129250575
> Skype: pearlbear
> Jabber: pearlbear@transactim.net
>
> "I see all the different religious traditions as paths for the
> development of inner peace, which is the true foundation of world
> peace. These ancient traditions come to us as a gift from our common
> past. Will we continue to cherish it as a gift and hand it over to the
> future generations as a legacy of our shared desire for peace?" - His
> Holiness the Dalai Lama
>
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