Altering views by using the INSTEAD OF trigger
Typically, you can only do normal insert, update, and delete operations on specific types of views, but you can use the INSTEAD OF trigger to extend the updatability of views.
About this task
Unlike other forms of triggers that are defined only on tables, INSTEAD OF triggers are defined only on views. If you use the INSTEAD OF trigger, the requested update operation against the view is replaced by the trigger logic, which performs the operation on behalf of the view.
Procedure
To alter a view by using the INSTEAD OF trigger:
Issue the CREATE TRIGGER statement and specify the INSTEAD
OF trigger for insert, update, and delete operations on the view.