InterBase database: Protect your data! Introducing InterBase Exceptions

InterBase has the ability to raise customized exceptions when something happens that you want to prevent. In this tutorial, we will learn how we can implement advanced business logic into a database to ensure that only valid data is entered. The example we follow ensures that data entered in a Tax ID field passed advanced check sum checking, and prevents the data being added if it fails the checks. Although you don't need to use UDF, this simple example is a natural follow on to the Triggers and UDF tutorials.