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

From: Jon Heggland <heggland_at_idi.ntnu.no>
Date: Thu, 24 Nov 2005 15:20:23 +0100
Message-ID: <MPG.1defea87a019206098970a@news.ntnu.no>


In article <43859d3d$1_at_news.fhg.de>, spam_at_conceptoriented.com says...
> Jon Heggland schrieb:
> > In article <1132798608.160942.270970_at_o13g2000cwo.googlegroups.com>,
> > michael_at_preece.net says...
> >
> >>If you have a text/string field and it can have an empty string what
> >>have you got? What is the value of the data? How does that value differ
> >>from "no value at all"? Question mark.
> >
> >
> > Are two variables/"fields" (of the same type) with "no value at all"
> > equal?
>
> The question does not make sense because we cannot talking about things
> that do not exist.

I postulate that the two variables *do* exist, but that they contain "no value at all" (if such a thing is possible); alternatively, that they contain the empty string. Thus, the question does makes sense.

Or do you somehow interpret michael's question to imply that if a variable contains the empty string, the variable does not exist?

> In particular, it does not make sense to ask if two
> things that do not exist are equal or not. Why not to ask then if two
> records that have not been created yet (or have been already deleted)
> are equal?

I agree that if two variables don't exist, we cannot compare them. But that's not the issue.

-- 
Jon
Received on Thu Nov 24 2005 - 08:20:23 CST

Original text of this message

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