Re: Oracle NULL vs '' revisited

From: Serge Rielau <srielau_at_ca.ibm.com>
Date: Fri, 17 Aug 2007 13:38:47 -0400
Message-ID: <5im4otF3pvr7lU1@mid.individual.net>

Thomas Kellerer wrote:
>
>
> Matthew Harrison wrote on 17.08.2007 16:49:

>> Ok, I'm developing another oracle application where the distinction 
>> between NULL and '' will be important.

>
> I would be interested: if this is important for character columns, then
> I assume this is important for other columns as well.
> How do you implement that distinction for e.g. NUMBER or DATE columns?
If I get an assignment and I hand in an empty sheet that would be well empty. I typed zero characters.
If I don't hand it in it is missing. It is not decidable whether my work is good or bad, long short.. there is the NULL. For numbers I think one can reasonably argue that 0 is the equivalent of empty.
I don't think that there is a similar "empty" concept for dates.

Question: If empty strings make no sense for VARCHAR, why have them for CLOBs? AFAIK Oracle has helper functions to produce empty lobs.

Cheers
Serge

PS: The Romans had some severe issues "getting" the concept of 0. Today we take it for granted. Perhaps '' is no different :-)

-- 
Serge Rielau
DB2 Solutions Development
IBM Toronto Lab

Received on Fri Aug 17 2007 - 12:38:47 CDT