Re: Primary Key of type string ?

From: Frank van Bortel <frank.van.bortel_at_gmail.com>
Date: Thu, 31 May 2007 19:28:03 +0200
Message-ID: <f3n0j3$e6$1@news2.zwoll1.ov.home.nl>

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Walt wrote:
[snip!]
> Except for simple small code tables, use an ordinal (Number(10) is
> good), generated by a sequence. Do not put "meaningful" data in your
> primary key, because everything that has external meaning is subject to
> change and should be an attribute, not a key.
>
> A classic example is Social Security Number - if you've used that as a
> primary key for your person table, you're in a world of hurt.
>
> //Walt

As you pointed out: the values, that make up primary key columns, should never change. I'd like to add: they should be unique.

Not sure about US based SSN's, but the Dutch counterpart sure ain't unique for reasons that make me doubt is SSN's are.

-- Regards, Frank van Bortel

Top-posting is one way to shut me up...
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