Re: Unique constraint and NULL values

From: Frank Piron <empty_at_zero.nil>
Date: Thu, 21 Oct 2004 16:09:38 +0200
Message-ID: <opsf74act8m0et4w_at_news.online.de>


Am Thu, 21 Oct 2004 09:37:42 -0400 schrieb Mark C. Stock <mcstockX_at_Xenquery .com>:
>
>
> did you try a standard UNIQUE constraint on the column?
>
> unlike SQL-Server (unless they've changed it since I last worked on it),
> Oracle processes null values properly in this scenario (i.e., one NULL
> value
> is never consider equal to another NULL value)

Yes, but it's a matter of convention because "NULL <> NULL" evaluates to null and thus is also not true. So two null values should never be considered different.

> ++ mcs
>
>

-- 
Frank Piron,
etfrankatkonaddotn
(leftrotate two)
Received on Thu Oct 21 2004 - 16:09:38 CEST

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