Re: ID field as logical address

From: Bernard Peek <bap_at_shrdlu.com>
Date: Mon, 1 Jun 2009 16:11:07 +0100
Message-ID: <2hlWqCcL++IKFw36_at_shrdlu.com>


In message <ImwUl.30133$PH1.14509_at_edtnps82>, paul c <toledobythesea_at_oohay.ac> writes
>Walter Mitty wrote:
>> "Brian Selzer" <brian_at_selzer-software.com> wrote in message
>...
>>> {{L:Smith, F:Mary, Stat:Single},
>>> {L:Jones, F:Mary, Stat:Married}}
>>>
>>> and is then assigned the value,
>>>
>>> {{L:Smith, F:Mary, Stat:Divorced},
>>> {L:Jones, F:Mary, Stat:Married}}
>>> ...
>...
>>> Note that the introduction of an autogenerated ID eliminates all
>>>confusion:
>>> ...
>
>"autogenerated ID eliminates all confusion", what a laugh, almost
>sounds like a sleeping pill slogan.

I think I'd say that an autogenerated ID hides the problem, or at least moves it around. Instead of asserting that the key always refers to an instance within the universe of discourse, you substitute an autonumber field and make the same assertion.

In an entity the key refers unambiguously to an instance within the universe. When you build a database table that is an aspiration.

-- 
Bernard Peek
Received on Mon Jun 01 2009 - 17:11:07 CEST

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