select
e.last_name,
e.first_name,
dm.dept_name
from
employees e
left join dept_emp d on e.emp_no = d.emp_no
left join departments dm on dm.dept_no = d.dept_no

select
e.last_name,
e.first_name,
dm.dept_name
from
employees e
left join dept_emp d on e.emp_no = d.emp_no
left join departments dm on dm.dept_no = d.dept_no