DELIMITER $$

CREATE PROCEDURE usp_get_employees_by_salary_level(type_salary VARCHAR(50))
BEGIN
	CASE WHEN type_salary LIKE ('Low') THEN SELECT e.first_name, e.last_name FROM employees AS e WHERE e.salary < 30000;
	WHEN type_salary LIKE ('Average') THEN SELECT e.first_name, e.last_name FROM employees AS e WHERE e.salary <= 50000;
	ELSE SELECT e.first_name, e.last_name FROM employees AS e WHERE e.salary > 50000;
	END
END $$