DELIMITER //
CREATE TRIGGER `return_date` AFTER INSERT ON `days_of_the_week`
FOR EACH ROW
BEGIN
	IF new.DOTW <3
		THEN INSERT INTO `dateflight` (`id_DOTW`, `DateFlight`) VALUES ((NEW.idDOTW), '2014-05-17');
	ELSEIF new.DOTW > 3
		THEN INSERT INTO `dateflight` (`id_DOTW`, `DateFlight`) VALUES ((NEW.idDOTW), '2014-05-18');
END IF;
END//

DELIMITER //
CREATE TRIGGER `return_date` AFTER INSERT ON `days_of_the_week`
FOR EACH ROW
BEGIN
	IF new.DOTW <= 3
		THEN INSERT INTO `dateflight` (`id_DOTW`, `DateFlight`) SELECT (NEW.idDOTW), '2014-05-17'
		FROM `dateflight` WHERE NOT EXISTS
		(SELECT * FROM `dateflight` WHERE `id_DOTW`= (NEW.idDOTW) AND `DateFlight` = '2014-05-17') LIMIT 1;
	ELSEIF new.DOTW > 3
		THEN INSERT INTO `dateflight` (`id_DOTW`, `DateFlight`) SELECT (NEW.idDOTW), '2014-05-18'
		FROM `dateflight` WHERE NOT EXISTS
		(SELECT * FROM `dateflight` WHERE `id_DOTW`= (NEW.idDOTW) AND `DateFlight` = '2014-05-18') LIMIT 1;
END IF;
END//

 IF new.DOTW <= 3

IF new.DOTW = 3