MySQL allows to specify from which table the matching rows must be deleted
-- remove only the employees
DELETE e
FROM Employees e JOIN Department d ON e.department_id = d.department_id
WHERE d.name = 'Sales'
-- remove employees and department
DELETE e, d
FROM Employees e JOIN Department d ON e.department_id = d.department_id
WHERE d.name = 'Sales'
-- remove from all tables (in this case same as previous)
DELETE
FROM Employees e JOIN Department d ON e.department_id = d.department_id
WHERE d.name = 'Sales'