DELIMITER $$
CREATE OR REPLACE DEFINER=`root`@`localhost` FUNCTION `util`.`hasDateOverlapped`(vSarted1 DATE, vEnded1 DATE, vSarted2 DATE, vEnded2 DATE)
RETURNS tinyint(1)
DETERMINISTIC
BEGIN
RETURN GREATEST(vSarted1, vSarted2) <= LEAST(vEnded1,vEnded2);
END$$
DELIMITER ;