Triggers

Preparing for the 70-461 exam I read about triggers. They are store procedures that are automatically invoked upon some actions on a table. A kind of event handler for SQL-tables. They can be used to enforce rules that are more complex than what would fit in a CHECK constraint. They can also be used for any other kind of action that applies every time the data is edited. The max. depth for circular references is 32 calls and returning results from a trigger is deprecated.