Re: Null in subquery returns no records

From: ben brugman <ben_at_niethier.nl>
Date: Tue, 10 Feb 2004 10:37:10 +0100
Message-ID: <4028a647$0$1409$4d4ebb8e@read.news.nl.uu.net>

"Mikito Harakiri" <mikharakiri_at_iahu.com> wrote in message news:7qXVb.46$St1.210_at_news.oracle.com...
> "Paul G. Brown" <paul_geoffrey_brown_at_yahoo.com> wrote in message
> news:57da7b56.0402091702.5a3fe316_at_posting.google.com...
> [B]: Codd himself first broached the subject of missing information and
> unknown or null values. Now, once you have missing values you've
got
> to
> figure out what to do about them. Eventually it was decided that
> anytime you did anything with a variable whose value was marked
> as "unknown", the result would also be "unknown".

I do disagree with that :

Null or true evaluates to True and
Null and false evaluates to False

ben brugman

>
> That was the design. The implementation turned out to be
>
> "Anytime you did anything with a variable whose value was marked
> as 'unknown', the result would be surprising for the end user".
>
>
Received on Tue Feb 10 2004 - 03:37:10 CST