Another Solution to the Excercise

Is is a correct one?

DELIMITER $$
DROP FUNCTION IF EXISTS f_emp_info;
CREATE FUNCTION f_emp_info (f_first_name VARCHAR(255), f_last_name VARCHAR(255)) RETURNS DECIMAL(10,2)
DETERMINISTIC NO SQL READS SQL DATA
BEGIN
DECLARE f_latest_contract_salary DECIMAL(10,2);

SELECT 
    s.salary INTO f_latest_contract_salary
FROM
    salaries s
WHERE
    s.emp_no = (SELECT 
            e.emp_no
        FROM
            employees e
        WHERE
            e.last_name = f_last_name
                AND e.first_name = f_first_name)
        AND s.from_date IN (SELECT 
            MAX(s.from_date)
        FROM
            salaries s
                JOIN
            employees e ON e.emp_no = s.emp_no
        WHERE
            e.last_name = f_last_name
                AND e.first_name = f_first_name);
                
RETURN f_latest_contract_salary;
END$$
DELIMITER ;

SELECT employees.f_emp_info('Aruna', 'Journel');