Advantages of INSTEAD OF Triggers

You can write a trigger for a view, but if the view is updateable it isn't necessary. Triggers on the underlying table fire automatically. (Of course, you may have your own reasons why you want triggers on such views.) Of all the advantages INSTEAD OF triggers offer, the main one is that they allow views that would normally not be updateable to support updates. A view that involves multiple tables must use an INSTEAD OF trigger to support inserts, updates, and deletes that reference data in more than one table. For example, you can write an INSTEAD OF trigger that inserts rows in multiple tables from a single view.

Another important advantage to INSTEAD OF triggers is that they allow you to write logic that accepts parts of a batch while rejecting other parts. Finally, INSTEAD OF triggers allow you to take some alternative action in the event of some particular condition that the application defines as an error.