Received: from localhost (postgresql.org [64.49.215.8])
	by postgresql.org (Postfix) with ESMTP id 1C5BA475D00
	for <pgsql-sql@postgresql.org>; Fri,  8 Nov 2002 23:30:09 -0500 (EST)
Received: from web80307.mail.yahoo.com (web80307.mail.yahoo.com
 [66.218.79.23])
	by postgresql.org (Postfix) with SMTP id 4B8CE475C3D
	for <pgsql-sql@postgresql.org>; Fri,  8 Nov 2002 23:30:08 -0500 (EST)
Message-ID: <20021109043013.3645.qmail@web80307.mail.yahoo.com>
Received: from [203.87.150.116] by web80307.mail.yahoo.com via HTTP;
	Fri, 08 Nov 2002 20:30:13 PST
Date: Fri, 8 Nov 2002 20:30:13 -0800 (PST)
From: Ludwig Lim <lud_nowhere_man@yahoo.com>
Subject: Some more weird NULL behavior
To: PostgreSQL Mailing List <pgsql-sql@postgresql.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200211/151
X-Sequence-Number: 10293

Hi:

  I tried the following:
  CREATE TABLE x(
       a  NUMERIC(5,0),
       b  VARCHAR(5)
  );

  CREATE TABLE y(
       a  INTEGER,
       b  VARCHAR(5)
  );

  INSERT INTO x(b) VALUES ('LUDZ');
  INSERT INTO y(b) VALUES ('TEST');

  SELECT x.b,y.b FROM x,y WHERE x.a=y.a 
  returns zero rows.

  However:
  SELECT b FROM x WHERE a IS NULL returns 'LUDZ'
  SELECT b from y WHERE a IS NULL returns 'TEST'

  I also tried
  SELECT x.b,y.b
  FROM x,y
  WHERE x.a = CAST(y.a AS INTEGER);

  But it also returns zero rows.


Thank you in advance,
ludwig.
  

__________________________________________________
Do you Yahoo!?
New DSL Internet Access from SBC & Yahoo!
http://sbc.yahoo.com