题解 | #查找所有已经分配部门的员工的last_name和first_name以及dept_no#
获取所有非manager的员工emp_no
http://www.nowcoder.com/practice/32c53d06443346f4a2f2ca733c19660c
select e.emp_no
from employees e
where e.emp_no not in
from employees e
where e.emp_no not in
(select emp_no from dept_manager)
考察where子句中的子查询
