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Re: "=" operator vs. "IS"

From: Michael A Nachbaur <mike(at)nachbaur(dot)com>
To: Stefan Weiss <spaceman(at)foo(dot)at>
Cc: pgsql-sql(at)postgresql(dot)org
Subject: Re: "=" operator vs. "IS"
Date: 2004-06-28 22:28:08
Message-ID: 200406281528.08526.mike@nachbaur.com (view raw or flat)
Thread:
Lists: pgsql-sql
On June 28, 2004 03:02 pm, Stefan Weiss wrote:
> I'm just curious - why is it not possible to use the "=" operator to
> compare values with NULL? I suspect that the SQL standard specified
> it that way, but I can't see any ambiguity in an expression like "AND
> foo.bar = NULL". Is it because NULL does not "equal" any value, and the
> expression should be read as "foo.bar is unknown"? Or is there something
> else I'm missing?

As far as I have been able to tell, it is one of those quirks about SQL that 
you shouldn't bother trying to understand.  It just IS.  <rimshot/>

-- 
Michael A. Nachbaur <mike(at)nachbaur(dot)com>
http://nachbaur.com/pgpkey.asc

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