[Leetcode]Department Highest Salary

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

1.

select d.Name as Department, e.Name as Employee, e.Salary as Salary  
from Employee e, Department d ,  
(select DepartmentId ,MAX(Salary) as Salary from Employee group by DepartmentId  ) t  
where e.DepartmentId=t.DepartmentId and e.Salary=t.Salary and d.Id=e.DepartmentId;  

2.

# Write your MySQL query statement below

SELECT d.Name AS Department, e.Name AS Employee, t.Salary 

FROMEmployee e 

INNER JOIN (SELECT DepartmentId, MAX(Salary) 

AS Salary FROM Employee GROUP BY DepartmentId) t

USING(DepartmentId, Salary)

INNER JOIN Department d

ON d.id = t.DepartmentId