Re: So what's null then if it's not nothing?
Date: 25 Nov 2005 01:49:04 -0800
Jon Heggland wrote:
> In article <1132867508.797608.286670_at_o13g2000cwo.googlegroups.com>,
> michael_at_preece.net says...
> > Any two variables/"fields" (of any type) with "no value at all" are,
> > indeed, equal.
> Ok. Let's say that the empty string can be called "no value at all" for
> a text variable. What is "no value at all" for an integer variable?
Well Jon - I'd say they're both NULL. NULL is type-less. In the case of "no value at all" for an integer variable we can't store an empty string so we would store NULL. I know a lot of educated people will tell me that NULL, when compared to any other value, results in Unknown. I'd agree - if I agreed that NULL was unknown - or missing - or absent - or not, in fact, data. I believe that NULL is, correctly, "no value at all". We store something on a database because we know something. We can know something is empty. We can't know anything about something that doesn't exist. We have no facts about it. We have no data.
Mike. Received on Fri Nov 25 2005 - 10:49:04 CET