cascade delete in postgres

[nightowl]

I have a couple of tables from which I would like to have a delete cascade throught the tables ... deleting a record from table A should result in the deletion of all records in table B which reference the record in A.

How can I do this the best way? My tables already exist ... any way to implement this without having to rebuild them and losing information?

And what would have been the best way to do it if I had known this upfront?

[nnichols]

I don't know much about PgSQL but with Oracle you can alter a table to add constraints.

So it doesn't matter what stage of development you're at. Just add the constraints. It is worth doing a backup of your db first, just in case it all goes "tits-up".

Sorry I can't give you more help, but I've never user PgSQL.

[nnichols]

Having checked the PgSQL manual, it would be something like this -

ALTER TABLE tbl_name
ADD CONSTRAINT constraint_name FOREIGN KEY (col_name) REFERENCES ref_tbl_name(ref_col) MATCH FULL ON DELETE CASCADE

Hope this helps 😉