Re: So what's null then if it's not nothing?

From: <michael_at_preece.net>
Date: 24 Nov 2005 13:57:32 -0800
Message-ID: <1132869452.122091.16650@g49g2000cwa.googlegroups.com>

FrankHamersley wrote:

> michael_at_preece.net wrote:
> > Hugo Kornelis wrote:
> >>On Wed, 23 Nov 2005 01:09:56 GMT, Frank Hamersley wrote:
> >>>Hugo Kornelis wrote:
> >>>[..]

[snip]

> >>>Is "<Person><Name>Hugo Kornelis</Name></Person>" the same as
> >>>"<Person><Name>Hugo Kornelis</Name><Birthday></Birthday></Person>"?
> >>

[snip]

> >>I the first XML string, there is no Birthday attribute
> >>for me. It's missing. In SQL, this would be represented by NULL in the
> >>table, or my omitting the row if the birthday were stored in a seperate
> >>table.
> >
> > Omitting the row sounds right. Using NULL is certainly wrong. The thing
> > doesn't exist. Nor does <WhatYouDidLastNight/>. Using NULL for
> > everything that doesn't exist would take up a considerable amount of
> > storage space - like the size of the known universe and more.

> Everything after the 1st sentence of the preceding para itself is worthy
> of NULL. Nuff said!

>

Sorry - no. Not enough said by a long chalk. Everything stored on a database is a known fact. What does datum/data actually mean? It is ridiculous to store the "fact" that we don't know something. Only inadequacies in a model can come anywhere near accounting for a need to do this.

[snip]

Mike. Received on Thu Nov 24 2005 - 15:57:32 CST