如何在MySQL函数中引发错误

DELIMITER //
CREATE FUNCTION `raise_error`(p_value INT) RETURNS INT
BEGIN
  IF p_value < 0 THEN
    SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'Input value cannot be negative';
  END IF;
  RETURN p_value;
END //
DELIMITER ;

DELIMITER //
CREATE PROCEDURE `test_raise_error`()
BEGIN
  DECLARE v_value INT DEFAULT -1;
  BEGIN
    SELECT `raise_error`(v_value) INTO v_value;
  END;
EXCEPTION
  WHEN SQLSTATE '45000' THEN
    SELECT 'Error: Input value cannot be negative';
END //
DELIMITER ;