Re: Separate PK in Jxn Tbl?
From: David W. Fenton <XXXusenet_at_dfenton.com.invalid>
Date: 30 Jan 2008 00:41:30 GMT
Message-ID: <Xns9A34C862CF658f99a49ed1d0c49c5bbb2_at_64.209.0.92>
>> >> trick, although in large cities that might not do it, either.
>>
>> > Huh? You think there are some pairs of people who are getting
>> > married more than once on the same day?
>>
>> People with the same names could be getting married on the same
>> day in the same place, yes.
>
> The schema doesn't have any names in it.
Date: 30 Jan 2008 00:41:30 GMT
Message-ID: <Xns9A34C862CF658f99a49ed1d0c49c5bbb2_at_64.209.0.92>
Marshall <marshall.spight_at_gmail.com> wrote in news:e61f768f-1268-4f95-9712-1c65c1c65618_at_n20g2000hsh.googlegroups.co m:
> On Jan 28, 3:31 pm, "David W. Fenton" > <XXXuse..._at_dfenton.com.invalid> wrote:>> >> use Postal Code in place of place, and that might do the
>> >> And it all leaves aside the question of how you know that
>> >> husband/wife/date is always going to be unique. I think that
>> >> on any given day in the US, there are plenty of marriages in
>> >> which those three values will be identical. You could add
>> >> place. But then, in large cities, that might not be enough. So
>> >> trick, although in large cities that might not do it, either.
>>
>> > Huh? You think there are some pairs of people who are getting
>> > married more than once on the same day?
>>
>> People with the same names could be getting married on the same
>> day in the same place, yes.
>
> The schema doesn't have any names in it.
But the real-life entities do, so your schema must allow it, or it's an incorrect schema (for the application in question).
-- David W. Fenton http://www.dfenton.com/ usenet at dfenton dot com http://www.dfenton.com/DFA/Received on Wed Jan 30 2008 - 01:41:30 CET