Re: Oracle NULL vs '' revisited

From: Thomas Kellerer <FJIFALSDGVAF_at_spammotel.com>
Date: Sat, 18 Aug 2007 16:56:38 +0200
Message-ID: <5iofl7F3pcq82U1@mid.individual.net>

Serge Rielau wrote on 18.08.2007 16:23:
> Note that zero is an "empty set". NULL is the absence of the set itself.
> Look at VARRAY.
> When you accept a string as a set of characters and you model that as a
> VARRAY you can clearly see the distinction between an empty VARRAY (of
> CHAR(1)) and a NULL VARRAY.

I completely agree with you, the explanations you give are pretty good.

But still: why is everybody whining about not having this distinction with strings but no one ever complained about not having it for DATES? Why is one data type treated that differently (in terms of expectations) than the other?
*That's* what I don't understand.
I can fully understand that people might be confused about the unusual way (compared to other products) Oracle treats this.

I have come to like it, I actually prefer writing WHERE a IS NULL instead of WHERE a = '' OR a IS NULL to find out those rows where no information is available :)

Thomas Received on Sat Aug 18 2007 - 09:56:38 CDT