Are your trigger rules correct?

Triggers can be used to enforce integrity constraints. Users need only to specify some trigger rules to execute some amendment actions if an update violates a constraint. Rules may be written incorrectly, however it is hard to verify the rule correctness. We first propose the restoring condition to detect when the trigger rules can restore the validity of a given constraint after an update. Finally, we investigate the combined effect of the restoring conditions and propose a method to confirm which constraint may not be enforced correctly by the given trigger rules.