Обсуждение: updating a row referenced by a foreign key

Hi,

I have to update a row of data that is referenced via a foreign key
constraint from another table.

I cannot change the id of the referenced record because it is referenced
as a foreign key from another table.

Is there a simple way to update the row, and cascade the change to any
and all rows referencing this row as a foreign key? I searched on
cascade in the postgres docs and while I found references to deletion, I
didn't find one for updates.

Thanks,
Mike
--
Michael P. Soulier <michael_soulier@mitel.com>, 613-592-2122 x2522
"Any intelligent fool can make things bigger and more complex... It
takes a touch of genius - and a lot of courage to move in the opposite
direction." --Albert Einstein

Michael P. Soulier wrote:

> Is there a simple way to update the row, and cascade the change to any
> and all rows referencing this row as a foreign key? I searched on
> cascade in the postgres docs and while I found references to deletion, I
> didn't find one for updates.

http://www.postgresql.org/docs/current/static/ddl-constraints.html#DDL-CONSTRAINTS-FK

"Analogous to ON DELETE there is also ON UPDATE which is invoked when a
referenced column is changed (updated). The possible actions are the same."

--
Craig Ringer