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
);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: [EMAIL PROTECTED] AIM:pearlbear0 ICQ:129250575 Skype: pearlbear Jabber: [EMAIL PROTECTED]
"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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