题解 | 查找所有员工的last_name和first_name以及对应的dept_name

SELECT
    e.last_name,
    e.first_name,
    dm.dept_name
FROM
    employees AS e
    LEFT JOIN
    dept_emp AS de ON e.emp_no=de.emp_no
        LEFT JOIN
        departments AS dm ON de.dept_no=dm.dept_no；