From: mountain man <>
Date: Fri, 10 Jun 2005 01:00:20 GMT
Message-ID: <EC5qe.11729$>

"Jan Hidders" <> wrote:

>> What is lacking Codd's concise definition (rule 3)
>> for null data as "non-applicable data"?
> Read closely, that is not precisely how he defines it.

Are you referring to the part about being

"distinct from the empty character string or a string of blank characters
and distinct from zero

or any other number" (in Rule 3),

or are you referring to Codd's work elsewhere, like his "Extending the DB RM ..."?

Pete Brown
Falls Creek
Received on Fri Jun 10 2005 - 03:00:20 CEST

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