Re: deletion and many-to-one - Mailing list pgsql-novice

From Stephan Szabo
Subject Re: deletion and many-to-one
Date
Msg-id 20030809151019.A18519-100000@megazone.bigpanda.com
Whole thread Raw
In response to deletion and many-to-one  (Jennifer Vargas <w47fnpch02@sneakemail.com>)
List pgsql-novice
On Sat, 9 Aug 2003, Jennifer Vargas wrote:

> If you have a many-to-one relationship, such as a contact list where
> several people
> share an address, you may want to delete the child record once the last
> reference to
> it is gone. I don't see how to implement a reference-counting scheme in
> a database.
> What's the right way to accomplish this?

Probably a trigger on update or delete of the referencing table.  If
you're not worried about some of the multi-session concurrency problems,
it's a marginally simple plpgsql trigger.



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