DELIMITER $$
CREATE OR REPLACE DEFINER=`vn`@`localhost` FUNCTION `bs`.`tramo`(vDateTime DATETIME)
	RETURNS varchar(20) CHARSET utf8mb3 COLLATE utf8mb3_unicode_ci
	NOT DETERMINISTIC
	NO SQL
BEGIN

	DECLARE vTramo VARCHAR(20);
    DECLARE vHour INT;
    
    SET vHour = HOUR(vDateTime) ;
    
    SET vTramo =
		CASE 		
			WHEN vHour BETWEEN 0 AND 14 THEN 'Mañana'
            WHEN vHour BETWEEN 15 AND 24 THEN 'Tarde'
		END ;

RETURN vTramo;
END$$
DELIMITER ;
