Re: Negative Numbers in "Identity" or" Autonumber" fields
Date: Wed, 21 Mar 2007 16:38:44 GMT
Message-ID: <ocdMh.13173$PV3.136393_at_ursa-nb00s0.nbnet.nb.ca>
Marshall wrote:
> 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?
The basic ability to specify a value.
What about the model requires literals?
A model for expressing values has to have a way to express them. I don't think I understand your question.
> 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?
Everything.
> I'm not particularly attached to this construct, but if it is
> flawed I'd like to be able to put my finger right on it.
Received on Wed Mar 21 2007 - 17:38:44 CET