Mysql触发器使用过程中遇到的问题

DROP TRIGGER IF EXISTS `delete_actdata`;
CREATE DEFINER=`xxxxxx`@`localhost` TRIGGER `delete_actdata`
BEFORE DELETE ON `actdata`
FOR EACH ROW
BEGIN
DELETE FROM `great` WHERE `great`.`actid`=`actid`;
DELETE FROM `join` WHERE `join`.`actid`=`actid`;
DELETE FROM `get` WHERE `get`.`actid`=`actid`;
DELETE FROM `signup` WHERE `signup`.`actid`=`actid`;
DELETE FROM `vote_option` WHERE `vote_option`.`actid`=`actid`;
DELETE FROM `vote_users` WHERE `vote_users`.`actid`=`actid`;
END;