Re: Test if Data for a Field is UNIQUE

From: Martin Doherty <martin.doherty_at_undisclosed.com>
Date: Mon, 23 Jan 2006 14:43:34 -0500
Message-ID: <XBaBf.34$vq5.174@news.oracle.com>

Michael42 wrote:

>Hello,
>
>In Oracle 9i R2 on Solaris 8 I have a table (LOCATION) that has data.
>I want to create a Foreign Key (FK) and base it on an existing field
>(location_key) in this table. I am not 100% sure the values are unique
>(which is required to make it a FK for a child table).
>
>Can someone please share SQL that can be used to determine if the
>values in my LOCATION table field location_key field are UNIQUE?
>
>Thanks,
>
>Michael42
>
>
>

SELECT location_key, count(*)
FROM location
GROUP BY location_key
HAVING count(*) > 1 Received on Mon Jan 23 2006 - 13:43:34 CST