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

From: Jon Heggland <heggland_at_idi.ntnu.no>
Date: Thu, 15 Dec 2005 09:09:49 +0100
Message-ID: <MPG.1e0b433358f3ec93989747_at_news.ntnu.no>


In article <ic81q1dv2f5948ekq43g1r9vp8co2mh9hm_at_4ax.com>, hugo_at_pe_NO_rFact.in_SPAM_fo says...
> On Mon, 12 Dec 2005 11:10:23 +0100, Jon Heggland wrote:
>
> >Or perhaps they thought it was not a problem at all to use the same word
> >"NULL" for different concepts, behaving differently. After all, it is
> >obvious from the context when NULL means 'missing' and when it means
> >'unknown', no? :)
>
> Maybe - but in that case, I'd expect at least a footnote in the
> definition of "the null value". There is none. So *if* the ANSI commitee
> decided to use the word NULL for a different concept in "boolean"
> columns, they forgot to update the definition.

Yes, yes. I was just teasing vc by using his own argument against him.  

> It's possible, of course, but I'm more inclined to believe that they
> didn't realise they were breking the NULL propagation rule when they
> wrote it. Or they did realize but didn't care.

And/or they just read Codd the way I do. How do you other folks understand that article, by the way?

-- 
Jon
Received on Thu Dec 15 2005 - 09:09:49 CET

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