184. Department Highest Salary【leetcode】sql，join on

184. Department Highest Salary

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  |
+------------+----------+--------+

# Write your MySQL query statement below
SELECT     
    Department.name AS Department,
    Employee.name AS Employee,
    Salary 
FROM 
    Employee  
        JOIN 
    Department ON 
    Employee.DepartmentId =Department.Id  
WHERE
 (Employee.DepartmentId,Salary ) IN 
 (SELECT 
        DepartmentId ,MAX(Salary) 
  FROM 
        Employee 
  GROUP BY DepartmentId  )
 ;