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

From: David Cressey <david.cressey_at_earthlink.net>
Date: Tue, 29 Nov 2005 13:51:45 GMT
Message-ID: <R1Zif.6702$N45.1120@newsread1.news.atl.earthlink.net>

"Frank Hamersley" <terabitemightbe_at_bigpond.com> wrote in message news:cBYif.6655$ea6.2147_at_news-server.bigpond.net.au...
> David Cressey wrote:
>
> > Oracle chose to indicate a null by the "impossible values" method. For
> > example, A NULL in a NUMBER is represented by minus zero. A single
zero
> > byte is used to represent a NULL in a VARCHAR. Unfortunately, an empty
> > string, having length zero, gets the same representation. Oops!
> >
> > I don't know about Sybase.
>
> On zip research I am guessing the "impossible values" method given their
> propensity to force '' to ' ' to avoid embarassment and confusion.

Then again, maybe they got their model for "missing values" from Pick!

(ducking) Received on Tue Nov 29 2005 - 07:51:45 CST

Original text of this message

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