SQL实现LeetCode(184.系里最高薪水)
[LeetCode] 184.Department Highest Salary 系里最高薪水
The Employee table holds all employees. Every employee has an Id, a salary, and there is also a column for the department Id.
+----+-------+--------+--------------+
| Id | Name | Salary | DepartmentId |
+----+-------+--------+--------------+
| 1 | Joe | 70000 | 1 |
| 2 | Henry | 80000 | 2 |
| 3 | Sam | 60000 | 2 |
| 4 | Max | 90000 | 1 |
+----+-------+--------+--------------+
The Department table holds all departments of the company.
+----+----------+
| Id | Name |
+----+----------+
| 1 | IT |
| 2 | Sales |
+----+----------+
Write a SQL query to find employees who have the highest salary in each of the departments. For the above tables, Max has the highest salary in the IT department and Henry has the highest salary in the Sales department.
+------------+----------+--------+
| Department | Employee | Salary |
+------------+----------+--------+
| IT | Max | 90000 |
| Sales | Henry | 80000 |
+------------+----------+--------+
这道题让给了我们两张表,Employee表和Department表,让我们找系里面薪水最高的人的,实际上这题是Second Highest Salary和Combine Two Tables的结合题,我们既需要联合两表,又要找到最高薪水,那么我们首先让两个表内交起来,然后将结果表需要的列都标明,然后就是要找最高的薪水,我们用Max关键字来实现,参见代码如下:
解法一:
SELECT d.Name AS Department, e1.Name AS Employee, e1.Salary FROM Employee e1 JOIN Department d ON e1.DepartmentId = d.Id WHERE Salary IN (SELECT MAX(Salary) FROM Employee e2 WHERE e1.DepartmentId = e2.DepartmentId);
我们也可以不用Join关键字,直接用Where将两表连起来,然后找最高薪水的方法和上面相同:
解法二:
SELECT d.Name AS Department, e.Name AS Employee, e.Salary FROM Employee e, Department d WHERE e.DepartmentId = d.Id AND e.Salary = (SELECT MAX(Salary) FROM Employee e2 WHERE e2.DepartmentId = d.Id);
下面这种方法没用用到Max关键字,而是用了>=符号,实现的效果跟Max关键字相同,参见代码如下:
解法三:
SELECT d.Name AS Department, e.Name AS Employee, e.Salary FROM Employee e, Department d WHERE e.DepartmentId = d.Id AND e.Salary >= ALL (SELECT Salary FROM Employee e2 WHERE e2.DepartmentId = d.Id);
类似题目:
到此这篇关于SQL实现LeetCode(184.系里最高薪水)的文章就介绍到这了,更多相关SQL实现系里最高薪水内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家!
相关文章
Windows中MySQL数据库下载以及安装教程(最最新版)
这篇文章主要给大家介绍了关于Windows中MySQL数据库下载以及安装的相关资料,很多朋友刚开始接触mysql数据库服务器,对安装使用教程不太明白,这里给大家总结下,需要的朋友可以参考下2023-09-09MySQL5.7的sql脚本导入到MySQL5.5出错3种解决方案
笔者需要将使用MySQL5.7数据库的网站挪入winows服务器,目标服务器使用的是MySQL5.5,因为兼顾到以前的网站,MySQL不能升级。遇到MySQL5.7的sql脚本导入到MySQL5.5出错,总结了3种解决方案,总有一个方案适合你。2023-06-06在WIN命令提示符下mysql 用户新建、授权、删除,密码修改
一般情况下,修改MySQL密码,授权,是需要有mysql里的root权限的,本操作是在WIN命令提示符下,感兴趣的朋友可以参考下2013-11-11
最新评论