Date: Sun, 06 Jan 2008 12:04:47 GMT
"Carlos M. Calvelo" <c_jackal_at_hotmail.com> wrote in message
On 5 jan, 16:29, "David Cressey" <cresse..._at_verizon.net> wrote:
> "Roy Hann" <specia..._at_processed.almost.meat> wrote in message
> > "David Cressey" <cresse..._at_verizon.net> wrote in message
> > > I disagree. A null doesn't indicate that information exists. There is
> > > always the "not applicable" case
> > Which, I believe, is almost invariably the reason that nullable
> > get introduced in real databases. I continue to be baffled at this
> > preoccupation with flagging information that must exist but isn't known.
> > Discuss it if you must (I absolutely don't care about it), but don't
> > the more common problem.
> The "not applicable" case is the one that can be obviated by
That is indeed the obvious case.
> Even with full
> normalization there can be facts that the database doesn't know, and knows
> that it doesn't know. There can also be facts that the database doesn't
> know, and doesn't know that it doesn't know.
Here is a better explanation:
Sorry, could not resist.
I intended the veiled reference to Rumsfeld. Nice Catch.
Carlos Received on Sun Jan 06 2008 - 13:04:47 CET