Re: help on a query

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
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> Page: pageme@murrain.net
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>
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> Holiness the Dalai Lama
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