184. 部门工资最高的员工

题意

题目链接
查出每个部门最高工资

思路

子查询+group by

代码

select b.name as Department,a.name as Employee,salary
from Employee as a
left joinDepartment as b
ona.departmentId = b.id
where(a.departmentId, salary) in(select departmentId, Max(salary)fromEmployeegroup by    departmentId )