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

From: JOG <jog_at_cs.nott.ac.uk>
Date: 21 Mar 2007 16:30:12 -0700
Message-ID: <1174519812.758993.297780@y66g2000hsf.googlegroups.com>


On Mar 21, 9:49 pm, Bernard Peek <b..._at_alpha.shrdlu.com> wrote:
> On 2007-03-21, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:
>
>
>
> >> It's not particularly important if I don't get it, however; it's not
> >> a concept I care about at all.
>
> > How would you insert a new value if you have no literal for it?
>
> If you create a new record in a table (or for that matter a new object) then
> you get a new candidate identity with no additional steps required.
>
> Unless you know that the data in the table/object can only refer to one item
> then you can't be sure that your data is attached to the correct identity.
> Hence it's only a candidate. If you can be sure that there is a 1:1 mapping
> between identities and keys (for instance if the entity has a natural key)
> then you can be sure that you have attached the data to the correct
> identity.
>
> --
> b..._at_shrdlu.com
> In search of cognoscenti

I'm having trouble following this at all bernard. Entities have keys? Surely not - only relations have keys. Entities have identifying attributes. I also can't make head nor tail of what you mean when you talk about "attaching data to the correct identity", or why one would ever talk about 'objects' in reference to the rows of a relation. Perhaps I have misunderstood your intended meaning. Received on Wed Mar 21 2007 - 18:30:12 CDT

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