Re: Does Codd's view of a relational database differ from that ofDate&Darwin?[M.Gittens]
From: Jan Hidders <jan.hidders_at_REMOVETHIS.pandora.be>
Date: Tue, 07 Jun 2005 20:33:35 GMT
Message-ID: <zwnpe.113536$Be5.6694944_at_phobos.telenet-ops.be>
Date: Tue, 07 Jun 2005 20:33:35 GMT
Message-ID: <zwnpe.113536$Be5.6694944_at_phobos.telenet-ops.be>
Marshall Spight wrote:
>>Most of the time, in database context NULL denotes, as you point out,
>>the _absence_ of a value where you would expect one - still you are
>>freely using "NULL value" as a special kind of value.
>
> In fact, I don't think this is true. The SQL standard mostly takes
> the stand that NULL means "there is a value, but we don't know
> what it is."
- Jan Hidders