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Help selecting what is NOT in two tables

Started by benphp, Mar 04 2013 01:18 PM

SELECT ClassDetail.CLID
FROM ClassDetail
LEFT JOIN Classes
ON Classes.CLID = ClassDetail.CLID
WHERE Classes.CLID IS NULL

2 replies to this topic

Advanced Member

Posted 04 March 2013 - 01:18 PM

I have two tables:

Classes

CLID | CLDate

ClassDetail

CLID | Description | Instructor

I'm trying to figure out a single SQL statement that would return all CLIDs that exist in ClassDetail but NOT in Classes.

I'm in the process of fudging it in PHP, but I know there's a better way...

Thanks!

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