From: Michael A Nachbaur <mike@nachbaur.com>
To: Stefan Weiss <spaceman@foo.at>
Cc: pgsql-sql@postgresql.org
Subject: Re: "=" operator vs. "IS"
Date: Mon, 28 Jun 2004 15:28:08 -0700
Message-ID: <200406281528.08526.mike@nachbaur.com> (raw)
In-Reply-To: <200406290002.29099.spaceman@foo.at>
References: <200406290002.29099.spaceman@foo.at>
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@nachbaur.com>
http://nachbaur.com/pgpkey.asc
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-sql@postgresql.org
Cc: mike@nachbaur.com, spaceman@foo.at
Subject: Re: "=" operator vs. "IS"
In-Reply-To: <200406281528.08526.mike@nachbaur.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox