Skip site navigation (1) Skip section navigation (2)


From: Yury Bokhoncovich <byg(at)center-f1(dot)ru>
To: Bhuvan A <bhuvansql(at)yahoo(dot)com>
Cc: <pgsql-bugs(at)postgresql(dot)org>
Subject: Re:
Date: 2002-03-11 14:33:30
Message-ID: (view raw, whole thread or download thread mbox)
Lists: pgsql-bugs

On Mon, 11 Mar 2002, Bhuvan A wrote:

> > If you compare a NULL with anything you don't get a true value whether
> > you're comparing with =, !=, <, >, etc...  That's how it's defined to
> > behave.
> where did you get this definition of behaviour!? is it applicable only to
> postgres or ..?  its quite strange yaar!

it's standard SQL:
true and true gives true
true and false gives false
null and true gives null
null and false gives null

RTFM! Quick check on MySQL and MSSQL gives the same results.
AFAIK Interbase and Oracle behaves similarly.
So theory is confirmed by practice.
It is very amazing to listen about contrary thing, could you please tell
where you saw this?

WBR, Yury Bokhoncovich, Senior System Administrator, NOC of F1 Group.
Phone: +7 (3832) 106228, ext.140, E-mail: byg(at)center-f1(dot)ru(dot)
Unix is like a wigwam -- no Gates, no Windows, and an Apache inside.

In response to

  • at 2002-03-11 10:26:50 from Bhuvan A

pgsql-bugs by date

Next:From: Peter EisentrautDate: 2002-03-11 16:46:31
Subject: Re:
Previous:From: Tom LaneDate: 2002-03-11 14:28:36
Subject: Re: Bug #611: configure script produces incorrect results under IRIX

Privacy Policy | About PostgreSQL
Copyright © 1996-2017 The PostgreSQL Global Development Group