Example
Timing
There are two trigger action time modifiers :
BEFOREtrigger activates before executing the request,AFTERtrigger fire after change.
Triggering event
There are three events that triggers can be attached to:
INSERTUPDATEDELETE
Before Insert trigger example
DELIMITER $$
CREATE TRIGGER insert_date
BEFORE INSERT ON stack
FOR EACH ROW
BEGIN
-- set the insert_date field in the request before the insert
SET NEW.insert_date = NOW();
END;
$$
DELIMITER ;
Before Update trigger example
DELIMITER $$
CREATE TRIGGER update_date
BEFORE UPDATE ON stack
FOR EACH ROW
BEGIN
-- set the update_date field in the request before the update
SET NEW.update_date = NOW();
END;
$$
DELIMITER ;
After Delete trigger example
DELIMITER $$
CREATE TRIGGER deletion_date
AFTER DELETE ON stack
FOR EACH ROW
BEGIN
-- add a log entry after a successful delete
INSERT INTO log_action(stack_id, deleted_date) VALUES(OLD.id, NOW());
END;
$$
DELIMITER ;
