From: Peter Brawley
Date: October 26 2007 3:37pm
Subject: Re: Comparing keys in two tables
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Aaron

An exclusion join:

SELECT a.col
FROM a
LEFT JOIN b ON a.col=b.col
WHERE b.col IS NULL;

PB

Aaron Fischer wrote:
> Greetings!
>
> I have a problem that it seems would best be solved using subqueries.  
> However, I am working on a server that is running MySQL 3.23.58, so 
> subqueries are not available to me.
>
> What I am trying to do:
> I have two tables, each containing approximately 37,000 records.  I 
> want to compare the index field in Table A to the index field in Table 
> B.  I would like to see all records where the index in Table A does 
> not exist in Table B.
>
> Thoughts?  Suggestions?
>
> Much appreciated!
>
> -Aaron
>
>