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

From: <michael_at_preece.net>
Date: 20 Nov 2005 14:49:16 -0800
Message-ID: <1132526956.813999.94720@g14g2000cwa.googlegroups.com>

Hugo Kornelis wrote:

> On 20 Nov 2005 13:58:43 -0800, michael_at_preece.net wrote:
>
> >
> >Hugo Kornelis wrote:
> (snip)
> >> According to the ANSI specification, null has one and only one meaning:
> >> it's a marker to represent the absence of a value.
> >>
> >> So it's neither unknown, nor empty.
> >>
> >
> >This just seems plain wrong to me.
>
> Hi Mike,
>

[snip]

>
> (snipped rest of Pick description - we were discussing NULL in SQL,
> remember?)
>

...and how it has been the subject of much debate and the source of great confusion for many people. It is a bad standard.

I found this in the introduction to a book on samba:

http://us3.samba.org/samba/docs/man/Samba-HOWTO-Collection/pr03.html

"A good standard survives because people know how to use it. People know how to use a standard when it is so transparent, so obvious, and so easy that it become invisible. And a standard becomes invisible only when the documentation describing how to deploy it is clear, unambiguous, and correct. These three elements must be present for a standard to be useful, allowing communication and interaction between two separate and distinct entities to occur without obvious effort. ..... Clarity and unambiguity without correctness provide a technical nightmare. Correctness and clarity with ambiguity create maybe bits, and correctness and unambiguity without clarity provide a muddle through scenario."

There has been little or no significant debate about null in Pick circles. No need. It's clear. There now exists the possibility for confusion among Pickies now too though - owing to the erroneous definition of null given in the UniVerse reference manual and quoted elsewhere in this thread. The source of that confusion stems from an attempt to fit in with SQL's standard definition.

Look - my final word on this. Null is and should be defined as an empty set. Not missing or absent or unknown or anything else. I'll accept that it's not going to change in SQL-land - and that confusion will continue to reign. I'm aware of the problem now and can live with it. Really - it's not my problem.

Mike. Received on Sun Nov 20 2005 - 16:49:16 CST

Original text of this message

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