-20178 VIEW view-name ALREADY HAS AN INSTEAD OF operation TRIGGER DEFINED
Explanation
The view view-name already has an INSTEAD OF trigger defined for the indicated operation (UPDATE, DELETE, INSERT). Only one INSTEAD OF trigger can be defined for each operation on the view.
System action
The statement cannot be processed. The INSTEAD OF trigger was not created.
Programmer response
If a new INSTEAD OF trigger is required, drop the existing trigger and then create the new trigger.
SQLSTATE
428FP