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

From: Bernard Peek <>
Date: Sun, 20 Nov 2005 14:30:37 +0000
Message-ID: <>

In message <>, Hugo Kornelis <hugo_at_pe_NO_rFact.in_SPAM_fo> writes
>On Sat, 19 Nov 2005 23:19:58 +0000, Bernard Peek wrote:
>>In message <>, Gene Wirchenko
>><> writes
>>> Does an object exist? If it does, we get the answer yes. If it
>>>does not, we get the answer no. No NULL is needed.
>>Does my dog exist?
>Hi Bernard,
>Almost there. Almost.
>Does my dig exist? is a yes/no question. The answer to that is a boolean
>value. And booleans are not defined as a data type in SQL. There's a
>reason for that. All SQL data types can also accomodate a Null, but a
>boolean can't. All yes/no questions can allways be answered. Not with
>"yes" (true), "no" (false), or "no answer" (Null), but with "yes", "no",
>or "don't know" (unknown).
>A better example would be:
>What's the age (in whole years) of my dog?

OK, so what is it's age (in whole numbers)?

Bernard Peek
London, UK. DBA, Manager, Trainer & Author.
Received on Sun Nov 20 2005 - 15:30:37 CET

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