12.7. INSTEAD OF Triggers

A view comprising multiple base tables must use an INSTEAD OF trigger to support inserts, updates and deletes that reference data in the tables. See "create trigger" in Section A.7, “Productions”.

Based on the select transformation's complexity some times INSTEAD OF Triggers are automatically provided for the user when "UPDATABLE" OPTION on the view is set to "TRUE". However, using the CREATE TRIGGER mechanism user can provide/override the default behaviour.

CREATE TRIGGER ON CustomerOrders INSTEAD OF INSERT AS
   FOR EACH ROW
   BEGIN ATOMIC
   INSERT INTO Customer (...) VALUES (NEW.value ...);
   END