CREATE FUNCTION ufn_get_salary_level(salary DOUBLE)
RETURNS VARCHAR(20)
BEGIN
DECLARE salary_level VARCHAR(20);
CASE 
	WHEN salary < 30000 THEN SET salary_level := 'Low';
	WHEN salary <= 50000 THEN SET salary_level := 'Average';
	WHEN salary > 50000 THEN SET salary_level := 'High';
END CASE;
RETURN salary_level;
END