【领扣leetcode数据库】184. 部门工资最高的员工难度中等

最新推荐文章于 2020-02-15 01:00:01 发布

原创最新推荐文章于 2020-02-15 01:00:01 发布 · 3.4w 阅读

0 ·

CC 4.0 BY-SA版权

领扣leetcode 专栏收录该内容

17 篇文章

订阅专栏

本文介绍如何使用SQL查询从Employee和Department表中找出每个部门薪资最高的员工，通过使用子查询和窗口函数实现跨表联接并筛选最高薪资。

题目描述

Employee 表包含所有员工信息，每个员工有其对应的 Id, salary 和 department Id。

+----+-------+--------+--------------+
| Id | Name  | Salary | DepartmentId |
+----+-------+--------+--------------+
| 1  | Joe   | 70000  | 1            |
| 2  | Henry | 80000  | 2            |
| 3  | Sam   | 60000  | 2            |
| 4  | Max   | 90000  | 1            |
+----+-------+--------+--------------+

Department 表包含公司所有部门的信息。

+----+----------+
| Id | Name     |
+----+----------+
| 1  | IT       |
| 2  | Sales    |
+----+----------+

编写一个 SQL 查询，找出每个部门工资最高的员工。例如，根据上述给定的表格，Max 在 IT 部门有最高工资，Henry 在 Sales 部门有最高工资。

+------------+----------+--------+
| Department | Employee | Salary |
+------------+----------+--------+
| IT         | Max      | 90000  |
| Sales      | Henry    | 80000  |
+------------+----------+--------+

代码

/* Write your T-SQL query statement below */
select
Department
,Employee
,Salary
from
(
select 
    e.name as Employee
    ,d.name as Department
    ,Salary
    ,rank() over (partition by d.name order by salary desc) as rank
from employee e
left join department d
on e.departmentid=d.id
)t
where  rank=1
and Department is not null