What are Trigger ? How to invoke a trigger on Demands?
Trigger are special kind of store procedure that gets executed automatically when an INSERT, UPDATE or DELETE operation takes place on table
Trigger can't be invoke on demands, they get triggered only when an associated action(INSERT,UPDATE,DELETE) happens on table on which they are defined
Trigger are generally used to implement business rule, auditing,Trigger can also be used to extends the referential integrity checks; but whenever possible, use contraints for this purpose,instead of trigger contraints are much faster