Re: Primary Key

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On Mon, 26 Nov 2007 10:28:03 -0800 (PST)
Richard Broersma Jr <rabroersma(at)yahoo(dot)com> wrote:

> --- On Mon, 11/26/07, Joshua D. Drake <jd(at)commandprompt(dot)com> wrote:
>
> > In "theory" the item that would be a natural key
> > in this instance is the VIN. You would of course have
> > to make some kind of allowance for cars that don't
> > have a VIN (nothing in the last what...
> > 50 years?).
>
> So this is why the service stations always record my cars VIN number
> when I show up for oil changes. ;) Ofcourse, there is a whole
> industry built around auto theft where they restamp the stolen car
> with a differnt vin number. I wonder if these stolen cars end up
> with duplicated VIN numbers or if the VIN's they are given do not
> pass the the VIN check-sum (if such a think exists).

They may end up with duplicate VINs but that isn't really relevant as
at that point we know that one of the two (or six or whatever) cars are
invalid, thus the "natural" key is still valid and designed to alert us
if there is any potential problem :)

Sincerely,

Joshua D. Drake

>
> Regards,
> Richard Broersma Jr.
>
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