On 8 Jun 2001, at 11:41, Ray Drew wrote:

> -----Original Message-----
> From: Rohit Gupta [mailto:rohit@...]
> Sent: 08 June 2001 10:00
> To: ib-support@yahoogroups.com
> Subject: Re: [ib-support] Null
>
>
> >Not a feasable solution with literally thousands of filters assigned
> >everywhere. Besides the problme is the null. If a field is left
> >null, its order in the search is not teh same as blank or 0.
>
> >Using a statement such as (xx > 0) fails to find them and so does
> >(xx<= 0).... it is illogical. It should be in one or the other set.
>
> Not so. Null means its not a value or unknown, so it can't be in
> either set. This is something you need to consider at design time.
> Defining the column as not null and defaulting to 0 might be a
> solution, depending on what your problem is. Jo Celko gives a good
> description of the problems of allowing nulls in one of his books.
> Can't remember which one off hand.
>
It was "Instant SQL Programming"

In case somone wants to find the book,
Publisher: Wrox Press
Author: Joe Celko
ISBN 1-874416-50-8

I have the book, nothing IB specific, but it has enough basic SQL,
that it's still quite useful.

Paul


Paul Schmidt,
Tricat Technologies
Email: paul@...
Website: www.tricattechnologies.com