Re: Weird Query

From: Marian Aldenhövel <marian_at_mba-software.de>
Date: Mon, 01 Aug 2005 15:59:42 +0200
Message-ID: <dcl9sh$l59$1@online.de>

Hi,

> It is very simply: WHERE column IS NOT NULL
> Nothing more.

And it does work fine.

> There is *NO* distiction in Oracle

(between NULL and an empty string)

Which makes IS NOT NULL the safe choice. I was confused because other systems do make a distinction here. Just for the record: A numeric zero is still different from a NULL value in Oracle is it?

> It is wrong expectation. You can blindly substitute '' by NULL, in that
> case you get 2 WHERE conditions
> WHERE "PP_LOCK"=NULL
> and
> WHERE "PP_LOCK"<>NULL
> both are wrong

I would never have tried these. I _know_ they are wrong :-).

Ciao, MM

-- 
Marian Aldenhövel, Rosenhain 23, 53123 Bonn. +49 228 624013.
http://www.marian-aldenhoevel.de
"It's easy to make a small fortune in aviation,
  provided you start with a big one"

Received on Mon Aug 01 2005 - 08:59:42 CDT