This section provides some examples of triggers.
The following trigger action copies a row from the flights table into the flight_history table whenever any row gets inserted into flights and adds the comment "inserted from trig1" in the status column of the flight_history table.
CREATE TRIGGER trig1
AFTER UPDATE ON flights
REFERENCING OLD AS UPDATEDROW
FOR EACH ROW
INSERT INTO flights_history
VALUES (UPDATEDROW.FLIGHT_ID, UPDATEDROW.SEGMENT_NUMBER,
UPDATEDROW.ORIG_AIRPORT, UPDATEDROW.DEPART_TIME,
UPDATED ROW.DEST_AIRPORT, UPDATEDROW.ARRIVE_TIME,
UPDATEDROW.MEAL, UPDATEDROW.FLYING_TIME, UPDATEDROW.MILES,
UPDATEDROW.AIRCRAFT,'inserted from trig1');
The following trigger action updates the FlightAvailability table after an update of the flights table by setting the flight_id column to the value of the flight_id column in the modified row. The update of the FlightAvailability table happens only if the triggering update actually changed the value of FLIGHTS.FLIGHT_ID.
CREATE TRIGGER FLIGHTSUPDATE
AFTER UPDATE ON flights
REFERENCING OLD AS OLD NEW AS NEW
FOR EACH ROW
WHEN (OLD.FLIGHT_ID <> NEW.FLIGHT_ID)
UPDATE FlightAvailability
SET FLIGHT_ID = NEW.FLIGHT_ID
WHERE FLIGHT_ID = OLD.FLIGHT_ID;