Re: Examples of SQL anomalies?
Date: Wed, 2 Jul 2008 14:54:04 -0700 (PDT)
On Jul 2, 2:28 pm, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:
> Marshall wrote:
> > On Jul 2, 1:39 pm, -CELKO- <jcelko..._at_earthlink.net> wrote:
> >>A scalar value has to have one and only one data type.
> > There are some decent type-theoretic reasons for this.
> > Do you know what they are, I wonder?
> Given that it is wrong, I doubt there are any. A scalar value has to
> have a unique most specific type, but nothing prevents that MST being a
> subtype of another more general type.
I stand corrected. I accidentally read the correct thing instead of what was actually written. (As it stands, the statement disallows the possibility of subtypes!)
In type theory, the term for this is "principle type."
> >>That is why Codd put NULLs into his type model.
> > Codd put NULL in his model because he didn't know
> > any better. Type theory has come a long way since
> > 1970. We now understand why 3VL is a bad idea,
> > and we now understand more general, more typesafe
> > ways to accomplish the few things it can do.
> Why? Oh why?
The guilty must be punished!
I'm sorry, but I just can't bring myself to post something that calls the fucking morons "fucking morons." I even type it in sometimes. "You fucking moron" I start, but then I backspace over it. It's a character flaw; I admit it.
Marshall Received on Wed Jul 02 2008 - 23:54:04 CEST