Попробуйте
DECLARE incorrect_load_type CONDITION FOR SQLSTATE '22012';
DECLARE EXIT HANDLER FOR incorrect_load_type
begin
SELECT 'Load type is incorrect';
end;
DECLARE EXIT HANDLER FOR SQLEXCEPTION, SQLWARNING
begin
SELECT 'SQLException encountered';
rollback;
end;
IF (v_load_type != 'CORRECT TYPE') THEN
SIGNAL incorrect_load_type;
END IF;