Re: Determin if cascade is being used - Mailing list pgsql-novice

From Tom Lane
Subject Re: Determin if cascade is being used
Date
Msg-id 9938.1129570077@sss.pgh.pa.us
Whole thread Raw
In response to Determin if cascade is being used  (Martin Foster <martin@ethereal-realms.org>)
Responses Re: Determin if cascade is being used  (Martin Foster <martin@ethereal-realms.org>)
List pgsql-novice
Martin Foster <martin@ethereal-realms.org> writes:
> Is there a way to tell in PL/PgSQL if the delete coming down the line is
> from a cascade delete?   I have a trigger, which when called will throw
> an error because the row its trying to change is now linked with an item
> which no longer exists.   The foreign key constraint fails since it was
> removed before underlaying components were.

This sounds like you're trying to do manual enforcement of a foreign key
relationship.  Wouldn't it be better to let the standard FK mechanism
handle it for you?

(But the short answer is no, I don't think you can tell that from
plpgsql, or even very reasonably from a C trigger.)

            regards, tom lane

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