[SQL] Automatic Deletes?

[Itai Zukerman]

Hi,

I have:

CREATE TABLE a ( id SERIAL, val INT4 ) ;

I would like to create some rules to keep "a" free from rows where
val == 0.  Something like:

  CREATE RULE a_insert
  AS ON INSERT TO a
  WHERE NEW.val = 0
  DO INSTEAD NOTHING ;

  CREATE RULE a_update
  AS ON UPDATE TO a
  WHERE NEW.val = 0
  DO INSTEAD
    DELETE FROM a
    WHERE id = NEW.id ;

Does this look right?  I think there should be a better way to express
the second rule...

Thanks,
-itai