-- TRIGGER BEFORE INSERT AT `evento`
DELIMITER $$

CREATE TRIGGER `before_insert_evento`
BEFORE INSERT ON `evento`
FOR EACH ROW 
BEGIN
DECLARE idEvent INT(3);
DECLARE yearEv INT(4);
SET NEW.nombrev=UCASE(NEW.nombrev);
SELECT YEAR(NEW.fechaev) INTO yearEv;
SELECT IFNULL(MAX(idev),0) + 1 FROM evento WHERE YEAR(fechaev) = yearEv INTO idEvent;
SET NEW.idev=idEvent;
END;$$

DELIMITER ;