UPDATE trigger

Fire after an UPDATE.

An UPDATE trigger fires when a row is updated. Both OLD and NEW are accessible.

CREATE TRIGGER log_change
AFTER UPDATE ON products
FOR EACH ROW
BEGIN
  INSERT INTO log VALUES (OLD.name, NEW.name);
END;

This query logs old and new name.

The trigger log_change is created.

UPDATE trigger — details

In an UPDATE trigger both OLD and NEW are used. Ideal for tracking changes.

For example, if OLD.price differs from NEW.price you record the price change in a history table with both values.

Write an AFTER UPDATE trigger: log OLD.name and NEW.name.

Show example solution

CREATE TRIGGER log_change
AFTER UPDATE ON products
FOR EACH ROW
BEGIN
  INSERT INTO log VALUES (OLD.name, NEW.name);
END

Add OLD

  INSERT INTO log VALUES (____.name, NEW.name);

Show answer

  INSERT INTO log VALUES (OLD.name, NEW.name);