MYSQL TRIGGERS EXAMPLE

 DELIMITER //

CREATE TRIGGER ProductSellPriceUpdateCheck 

    AFTER UPDATE  

    ON Products FOR EACH ROW  

BEGIN

IF NEW.SellPrice <= NEW.BuyPrice THEN

INSERT INTO Notifications(Notification,DateTime) 

VALUES(CONCAT(NEW.ProductID,' was updated with a SellPrice of ', NEW.SellPrice,' which is the same or less than the BuyPrice'), NOW()); 

    END IF;

END //

DELIMITER //

CREATE TRIGGER ProductSellPriceInsertCheck 

    AFTER INSERT  

    ON Products FOR EACH ROW  

BEGIN

IF NEW.SellPrice <= NEW.BuyPrice THEN

INSERT INTO Notifications(Notification,DateTime) 

VALUES(CONCAT('A SellPrice same or less than the BuyPrice was inserted for ProductID ', NEW.ProductID), NOW()); 

    END IF;

END //

DELIMITER //

CREATE TRIGGER NotifyProductDelete 

    AFTER DELETE   

    ON Products FOR EACH ROW   

INSERT INTO Notifications(Notification, DateTime) 

    VALUES(CONCAT('The product with a ProductID ', OLD.ProductID,' was deleted'), NOW()); 

END //

DELIMITER ;