fk problems with 0..n relations
This is a discussion on fk problems with 0..n relations within the pgsql Novice forums, part of the PostgreSQL category; --> >I just need to put MATCH SIMPLE in my fk, right?? > > > ----- Original Message ----- > ...
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04-17-2008, 10:20 PM
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 fk problems with 0..n relations >I just need to put MATCH SIMPLE in my fk, right?? > > > ----- Original Message ----- > From: "Bruno Wolff III" <bruno@wolff.to> > To: "Luis Silva" <lfs12@hotmail.com> > Cc: <pgsql-novice@postgresql.org> > Sent: Monday, December 05, 2005 4:55 AM > Subject: Re: fk problems with 0..n relations > > >> On Mon, Dec 05, 2005 at 01:45:37 -0000, >> Luis Silva <lfs12@hotmail.com> wrote: >>> I there, i'm having a problem. i have a table(1) that is connected with >>> two multiple table (2 and 3). the problem is that the table 1 might have >>> one of the tables (2 or 3, or both). how can i make this relationship in >>> sql. Resuming, table 1 as a 0..n relation with table 2 and 3. thanks in >>> advance. >> >> Normally you just have tables 2 and 3 refer to table 1 and not the other >> way >> around. >> >> If you need to make sure that the entry in table 1 corresponds to at >> least >> one entry in table 2 or table 3, then you can have table 1 refer to both >> table 2 and table 3, but allow nulls. Then you use a constraint to make >> sure at least one of the references is not null. >> > ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq      |
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