#先做门员工关系表

#在做员工姓名跟部门关系表
select  t1.last_name,t1.first_name,t2.dept_name
from 
    employees t1 
    left join 
    (
        select 
            c.emp_no,b.dept_name 
        from 
            dept_emp c join departments b 
            on c.dept_no=b.dept_no
            ) 
            t2 
            on t1.emp_no=t2.emp_no;