题解 | #查找在职员工自入职以来的薪水涨幅情况#
查找所有员工的last_name和first_name以及对应的dept_name
http://www.nowcoder.com/practice/5a7975fabe1146329cee4f670c27ad55
select t.last_name,t.first_name,t3.dept_name from employees t left join
(select * from departments t1 left join dept_emp t2 on t1.dept_no=t2.dept_no)t3
on t.emp_no =t3.emp_no