Re: Negative Numbers in "Identity" or" Autonumber" fields

From: David Cressey <cressey73_at_verizon.net>
Date: Thu, 22 Mar 2007 13:18:18 GMT
Message-ID: <umvMh.10830$DX5.7472@trndny06>

"Marshall" <marshall.spight_at_gmail.com> wrote in message news:1174494284.308650.131890_at_n59g2000hsh.googlegroups.com...
> On Mar 21, 8:28 am, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:
> > Marshall wrote:
> > > On Mar 21, 4:00 am, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:
> >
> > >>Marshall wrote:
> >
> > >>>On Mar 20, 10:31 am, "JOG" <j..._at_cs.nott.ac.uk> wrote:
> >
> > >>>>[...] Nothing in a
> > >>>>proposition should ever be hidden from the user. Propositions come
> >
> > >>>>from outside of the logical layer after all. If an attribute is an
> >
> > >>>>identifier then it clearly impacts on identifying items in the real
> > >>>>world.
> >
> > >>>I buy the "nothing should be hidden" argument, but I can't
> > >>>decide if a domain that only supports equality is hiding
> > >>>anything or not.
> >
> > >>It has to have at least one possible representation.
> >
> > > Can you elaborate? Why does it need at least one?
> > > What breaks if it doesn't?
> >
> > How does one express any literal without at least one possible
> > representation?

>
>

> Okay, sure, yes, that's a point. But that's more of a structural
> objection than a functional one. What breaks if a type doesn't
> have literals? What about the model requires literals?

>

> In the case of equality, I can point to what exactly breaks if
> a type doesn't support it: join. Specifically equijoin requires
> some kind of "equi-".

>

> What breaks if a type doesn't have literals?
>
Storing an instance of the type in a computer. This answer is so obvious that I think you must have considered it and discarded it. So I must be misunderstanding the question. Can you clarify?

> Received on Thu Mar 22 2007 - 08:18:18 CDT