Ошибка синтаксиса SQL?

DELIMITER $$
CREATE TRIGGER exh_locs_check
BEFORE INSERT on exhibits
FOR EACH ROW
BEGIN
DECLARE @exhibit_placements int;
SET @exhibit_placements = (SELECT COUNT(*)  FROM exhibits
  JOIN collections_locations
  ON exhibits.id_коллекции = collections_locations.id_коллекции
  WHERE exhibits.id = new.id
    GROUP BY exhibits.id);
IF (@exhibit_placements) = 0 THEN
  SIGNAL SQLSTATE '12345' SET MESSAGE_TEXT='Error';
  END IF;
END$$
DELIMITER ;