From: D'Arcy J.M. Cain <darcy@druid.net>
To: Andrew Sullivan <ajs@crankycanuck.ca>
Cc: pgsql-sql@postgresql.org
Subject: Re: Differentiate Between Zero-Length String and NULLColumn Values
Date: Tue, 30 Jan 2007 11:38:34 -0500
Message-ID: <20070130113834.fa8d09e0.darcy@druid.net> (raw)
In-Reply-To: <20070130142332.GA31905@phlogiston.dyndns.org>
References: <20070130131334.GD31676@phlogiston.dyndns.org>
<45BF584F.A3DD.0030.0@indicator.be>
<20070130142332.GA31905@phlogiston.dyndns.org>
On Tue, 30 Jan 2007 09:23:32 -0500
Andrew Sullivan <ajs@crankycanuck.ca> wrote:
> Hmm. Well, I'm not an Oracle guy, so I don't really know. All I
> know is that we occasionally get people coming from Oracle who are
> surprised by this difference. What I've been _told_ is that '' and
> NULL are under some circumstances (maybe integers?) the same thing,
> whereas of course ' ' and NULL are not. But since I'm not an Oracle
> user, people should feel free to ignore me :)
I don't have an Oracle installation here and I haven't used it much but
I wonder if they treat the following two statements differently.
SELECT * FROM table WHERE column IS NULL;
SELECT * FROM table WHERE column = NULL;
The latter violates the SQL spec and is not allowed by PostgreSQL
without setting a special flag. Is it possible that Oracle accepts "="
against NULL and also treats it slightly differently?
--
D'Arcy J.M. Cain <darcy@druid.net> | Democracy is three wolves
http://www.druid.net/darcy/ | and a sheep voting on
+1 416 425 1212 (DoD#0082) (eNTP) | what's for dinner.
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To: pgsql-sql@postgresql.org
Cc: darcy@druid.net, ajs@crankycanuck.ca
Subject: Re: Differentiate Between Zero-Length String and NULLColumn Values
In-Reply-To: <20070130113834.fa8d09e0.darcy@druid.net>
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