Re: Sql Question

[Charles Wilt <charles.wilt@xxxxxxxxx>]

John,

I agree, you shouldn't make a column NULL-able unless there's a
specific reason you need the NULL-able.

Charles


On Wed, Aug 18, 2010 at 10:19 AM, John Arnold (MFS)
<jarnold@xxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> The nature of null values is that they can only be found by a test for
> null values - they will never show up in a not equal test - if you have
> null values in your data you must test for values not equal and values
> are null.
>
> This is why my data base does not allow null values unless there is a
> good reason for something to contain null values.
>
>
>
> -----Original Message-----
> From: midrange-l-bounces@xxxxxxxxxxxx
> [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Alan Campin
> Sent: Tuesday, August 17, 2010 6:08 PM
> To: Midrange Systems Technical Discussion
> Subject: Sql Question
>
> I have an SQL statement that compares data in for one table in two
> different
> libraries. The SQL just says report any record where the initials are
> different but when I run it I get nothing.
>
> I had one record where the initials for in one record was Null and in
> the
> other FUL but the SQL reported them as equal. That doesn't make much
> sense.
>
> Does SQL bypass the test if one side is null? Isn't null just a absence
> of
> data so they would not be equal? Have I found a bug (A big one?
> --
> This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing
> list
> To post a message email: MIDRANGE-L@xxxxxxxxxxxx
> To subscribe, unsubscribe, or change list options,
> visit: http://lists.midrange.com/mailman/listinfo/midrange-l
> or email: MIDRANGE-L-request@xxxxxxxxxxxx
> Before posting, please take a moment to review the archives
> at http://archive.midrange.com/midrange-l.
>
> --
> This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list
> To post a message email: MIDRANGE-L@xxxxxxxxxxxx
> To subscribe, unsubscribe, or change list options,
> visit: http://lists.midrange.com/mailman/listinfo/midrange-l
> or email: MIDRANGE-L-request@xxxxxxxxxxxx
> Before posting, please take a moment to review the archives
> at http://archive.midrange.com/midrange-l.