How_to_retrieve_data_from_two_or_more_tables/demo-queries-from slides-15.sql

USE ex;

SELECT department_name AS dept_name, d.department_number AS d_dept_no,
           e.department_number AS e_dept_no, last_name
    FROM departments d 
        LEFT JOIN employees e 
        ON d.department_number = e.department_number
UNION
    SELECT department_name AS dept_name, d.department_number AS d_dept_no,
           e.department_number AS e_dept_no, last_name
    FROM departments d 
        RIGHT JOIN employees e 
        ON d.department_number = e.department_number
ORDER BY dept_name;