Re: one to many

Stephan Szabo wrote:

>On Sun, 16 May 2004, Dennis Gearon wrote:
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>>CC me please.
>>
>>How do I set up a one to many relationship in Postgres, (any DB for that
>>matter.)
>>
>>I.E., if a delete or update of a child table causes a row in the parent
>>table to no longer refer to any rows in the child table, to either cause
>>Postgres to error out or delete the parent? I can see it does it for
>>when a parent is upudated or deleted.
>>
>>
>
>I don't think there's any built in direct way to do this right now, but
>you could probably build triggers that would do it for you (the current
>foreign key triggers might give a starting point. You'd probably also
>want to use CREATE CONSTRAINT TRIGGER to be able to defer the trigger
>(similarly to how the foreign key deferred works).
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I didn't know you could set up triggers to be deferred! AWESOME! That
makes for some additional flexibility that I could use.

Thank you very much Stephen. I was beginnning to consider TRIGGERS as
the solution; Now I know that they will work.