| From: | Paul Makepeace <postgresql(dot)org(at)paulm(dot)com> |
|---|---|
| To: | PostgreSQL Novice <pgsql-novice(at)postgresql(dot)org> |
| Subject: | cascading backwards |
| Date: | 2003-05-08 21:55:16 |
| Message-ID: | 20030508215516.GA14445@mythix.realprogrammers.com |
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| Thread: | |
| Lists: | pgsql-novice |
If a table A contains a foreign key to table B is it possible to have
a DELETE remove the targetted row in B when there are no longer any
other references in A to it? Either with SQL or using some other
PostgreSQL facility.
As an example,
Body:
body_id data
1 "some news"
Page:
page_id body_id name
10 1 "news"
11 1 "recent news"
If page_id=10 is deleted, nothing extra happens. If page_id=11 is
deleted, body_id=1 goes with it.
Many thanks, Paul
--
Paul Makepeace ....................................... http://paulm.com/
"If kangaroos graduate, then it shall rain in ghana on my sweet
potatoes."
-- http://paulm.com/toys/surrealism/
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