Re: Separate foreign keys with shared ID space
From: Erland Sommarskog <esquel_at_sommarskog.se>
Date: Sat, 31 Jul 2004 22:11:00 +0000 (UTC)
Message-ID: <Xns953819DCF3B6Yazorman_at_127.0.0.1>
>
> Says who? Can you justify this statement?
Date: Sat, 31 Jul 2004 22:11:00 +0000 (UTC)
Message-ID: <Xns953819DCF3B6Yazorman_at_127.0.0.1>
[Quoted] Marshall Spight (mspight_at_dnai.com) writes:
> "Christian Antognini" <christian.antognini_at_trivadis.com> wrote in message
[Quoted] news:410affcf$1_at_post.usenet.com...
>> >> A PK should have no business meaning.
>
> Says who? Can you justify this statement?
Because most real-world look-like keys do not live up to the strict requirements of the primary keys in a database. They are too often nullable or non-unique. Person identification numbers such as SSN are a good example of both.
-- Erland Sommarskog, SQL Server MVP, esquel_at_sommarskog.se Books Online for SQL Server SP3 at http://www.microsoft.com/sql/techinfo/productdoc/2000/books.aspReceived on Sun Aug 01 2004 - 00:11:00 CEST