Why use triggers in MySQL?
In MySQL, a trigger corresponds to a set of actions running automatically when a particular change operation like SQL INSERT, UPDATE, or DELETE query is performed on a table.
BY Best Interview Question ON 20 Sep 2022
Example
CREATE TRIGGER data_backup BEFORE UPDATE ON users
FOR EACH ROW
BEGIN
IF NEW.amount < 0 THEN
SET NEW.amount = 0;
ELSEIF NEW.amount > 100 THEN
SET NEW.amount = 100;
END IF;
END;//