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Re: foreign vs primary key

From: Ewald Börger <h.a.e.borger_at_student.utwente.nl>
Date: Thu, 20 Sep 2001 09:39:44 +0200
Message-ID: <3BA99D40.F600BCE7@student.utwente.nl>


mikeg wrote:
> "Dan Star" <danstar_at_engman-taylor.com> wrote in message
> news:3ba90b40$0$12824$272ea4a1_at_news.execpc.com...
> > mikeg wrote:
> > > I have read a number of texts regarding the terms foreign and primary
> keys
> > > but I just can't get a feel for their uses.
> > > any help appreciated,
> >
> > Think of Parent-Child. The foreign key is a key in a table that is the
> > primary key in another table.

<snip>
>
> Thanks, I can see that but what is the significance? Why is it necessary to
> identify the foreign key? How are they used? Aren't primary keys enough?

Normally: yes, up till yesterday I never bothered (mysql doesn't even have support for it)... now I'm going to have an application *guess* what columns contain foreign keys 'cause the production database (SQL Server) I need to transfer doesn't have explicit foreign keys defined (even worse: columns don't even have consequent names :(

Ewald Received on Thu Sep 20 2001 - 02:39:44 CDT

Original text of this message

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