Re: One more time on ONE-TO-MANY

It sounds like you are referring to a RI (Referential Integrity) constraint
and if so one of the options when the constraint is defined is CASCADE
DELETE, i.e., delete the children rows then delete the parent row and this
is available in Postgres.

Is this what you were asking or did I mis-interpret your query?

Duane

-----Original Message-----
From: Dennis Gearon [mailto:gearond(at)fireserve(dot)net]
Sent: Wednesday, May 26, 2004 3:25 PM
To: pgsql-general(at)postgresql(dot)org
Subject: [GENERAL] One more time on ONE-TO-MANY

CC me, I'm digesting this list.

From:
http://www.sum-it.nl/cursus/dbdesign/english/intro030.php3
A quote:
' In addition *the database designer chooses* an action for delete:

* It's /only possible/ to delete a row in the one-table when there a
no more related many-rows.
* When deleting a row the RDBMS
<http://www.sum-it.nl/cursus/dbdesign/english/intro030.php3#rdbms>
/automatically/ deletes the related data in the many table. This
is called a /cascaded delete/.
* When deleting the last 'many' the RDBMS /automatically/ deletes
the related 'one' row.'

I'm pretty sure that Postgres does not support the last one
automatically. I shall have to do that one by either a chron script or a
post trigger.

Does anyone have experience with a database that will do the last one,
and what database would that be?

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