Supporting integrity constraints is essential for database systems. Integrity constraints are used to ensure that the data in a database complies with rules that have been set to establish accurate and acceptable information for a database. Triggers provide a very powerful and flexible means to realize effective constraint enforcing mechanisms. Implementing triggers based on constraint specifications follows some simple rules that are basically independent of a particular commercial database system. This paper gives these rules, which can be used to derive triggers from constraint specifications. A comparison of advantages of constraints and triggers is also given in this paper.
Deriving Triggers from Integrity Constraint Specifications in the Database Management Systems