past_price_trigger.sql

use AlexJohnChris;
DELIMITER //
DROP TRIGGER IF EXISTS past_p
//
CREATE TRIGGER past_p AFTER
UPDATE 
ON product 
FOR EACH ROW
BEGIN
   IF (not NEW.price <=> OLD.price) THEN
   INSERT INTO past_prices
      (barcode,past_price,time_of_change)
   VALUES
      (OLD.barcode, OLD.price, NOW());
END
IF;
END;//
DELIMITER ;