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 |
+------------+----------+--------+
分析
通过group by把每个部分的最高工资找出来，再通过连表，找到相应的员工名字和部门名字
代码
# Write your MySQL query statement below
SELECT
d.Name as 'Department',
e.Name as 'Employee',
e.Salary
FROM
(
SELECT
DepartmentId, max(Salary) as Salary
FROM Employee
GROUP BY DepartmentId
) m ,
Employee e,
Department d
WHERE
m.DepartmentId = e.DepartmentId AND m.Salary = e.Salary AND e.DepartmentId = d.Id
;
题目链接
https://leetcode-cn.com/problems/department-highest-salary/description/
