LeetCode_185_Department TOP Three Salaries.sql

Create table If Not Exists Employee (Id int, Name varchar(255), Salary int, DepartmentId int)
Create table If Not Exists Department (Id int, Name varchar(255))
Truncate table Employee
insert into Employee (Id, Name, Salary, DepartmentId) values ('1', 'Joe', '85000', '1')
insert into Employee (Id, Name, Salary, DepartmentId) values ('2', 'Henry', '80000', '2')
insert into Employee (Id, Name, Salary, DepartmentId) values ('3', 'Sam', '60000', '2')
insert into Employee (Id, Name, Salary, DepartmentId) values ('4', 'Max', '90000', '1')
insert into Employee (Id, Name, Salary, DepartmentId) values ('5', 'Janet', '69000', '1')
insert into Employee (Id, Name, Salary, DepartmentId) values ('6', 'Randy', '85000', '1')
insert into Employee (Id, Name, Salary, DepartmentId) values ('7', 'Will', '70000', '1')
Truncate table Department
insert into Department (Id, Name) values ('1', 'IT')
insert into Department (Id, Name) values ('2', 'Sales')



-- The Employee table holds all employees. Every employee has an Id, and there is also a column for the department Id.

-- +----+-------+--------+--------------+
-- | Id | Name  | Salary | DepartmentId |
-- +----+-------+--------+--------------+
-- | 1  | Joe   | 85000  | 1            |
-- | 2  | Henry | 80000  | 2            |
-- | 3  | Sam   | 60000  | 2            |
-- | 4  | Max   | 90000  | 1            |
-- | 5  | Janet | 69000  | 1            |
-- | 6  | Randy | 85000  | 1            |
-- | 7  | Will  | 70000  | 1            |
-- +----+-------+--------+--------------+
-- The Department table holds all departments of the company.

-- +----+----------+
-- | Id | Name     |
-- +----+----------+
-- | 1  | IT       |
-- | 2  | Sales    |
-- +----+----------+
-- Write a SQL query to find employees who earn the top three salaries in each of the department. For the above tables, your SQL query should return the following rows (order of rows does not matter).

-- +------------+----------+--------+
-- | Department | Employee | Salary |
-- +------------+----------+--------+
-- | IT         | Max      | 90000  |
-- | IT         | Randy    | 85000  |
-- | IT         | Joe      | 85000  |
-- | IT         | Will     | 70000  |
-- | Sales      | Henry    | 80000  |
-- | Sales      | Sam      | 60000  |
-- +------------+----------+--------+
-- Explanation:

-- In IT department, Max earns the highest salary, both Randy and Joe earn the second highest salary,
-- and Will earns the third highest salary. There are only two employees in the Sales department, 
-- Henry earns the highest salary while Sam earns the second highest salary.


-- # Write your MySQL query statement below

with temp as(
select d.Name as Department, e.Name as Employee, Salary, dense_Rank() over(partition by d.Name order by Salary desc) as Ranki from Employee e inner join Department d
on d.id =e.DepartmentId)
select Department, Employee, Salary  from temp where Ranki <=3