SELECT s.last_name AS employee_last_name, ss.reports_to AS manager_last_name FROM staff AS s LEFT JOIN staff AS ss ON s.employee_id=ss.reports_to GROUP BY 1, 2 SELECT DISTINCT s.last_name AS employee_last_name, ss.reports_to AS manager_last_name FROM staff AS s LEFT JOIN staff AS ss ON s.employee_id=ss.reports_to