Leetcode 185 All employees with the top three highest wages in the Department (July 4, 2022)

surface : Employee

±-------------±--------+
| Column Name | Type |
±-------------±--------+
| id | int |
| name | varchar |
| salary | int |
| departmentId | int |
±-------------±--------+
Id Is the primary key column of the table .
departmentId yes Department In the table ID The foreign key .
Each row of the table represents the employee's ID、 Name and salary . It also includes their department's ID.

surface : Department

±------------±--------+
| Column Name | Type |
±------------±--------+
| id | int |
| name | varchar |
±------------±--------+
Id Is the primary key column of the table .
Each row of the table represents the Department ID And department name .

Company executives are interested in who makes the most money in each department of the company . Of a department High income earners It refers to the salary of an employee in the... Of the Department Different In salary Top three .

Write a SQL Inquire about , Find out... In each department High paid employees .

With In any order Return result table .

The query result format is as follows .

Example 1:

Input :
Employee surface :
±—±------±-------±-------------+
| 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 |
±—±------±-------±-------------+
Department surface :
±—±------+
| id | name |
±—±------+
| 1 | IT |
| 2 | Sales |
±—±------+
Output :
±-----------±---------±-------+
| Department | Employee | Salary |
±-----------±---------±-------+
| IT | Max | 90000 |
| IT | Joe | 85000 |
| IT | Randy | 85000 |
| IT | Will | 70000 |
| Sales | Henry | 80000 |
| Sales | Sam | 60000 |
±-----------±---------±-------+
explain :
stay IT department :

• Max The highest salary
• Randy and Joe both earn the second highest unique salary
• Will's salary is the third highest

In the Sales Department :

• Henry's salary is the highest
• Sam's salary is the second highest
• There is no third highest salary , Because there are only two employees

source ： Power button （LeetCode）
link ：https://leetcode.cn/problems/department-top-three-salaries

MySQL Submission ：

# Write your MySQL query statement below
SELECT
    d.Name AS 'Department', e1.Name AS 'Employee', e1.Salary
FROM
    Employee e1
        JOIN
    Department d ON e1.DepartmentId = d.Id
WHERE
    3 > (SELECT
            COUNT(DISTINCT e2.Salary)
        FROM
            Employee e2
        WHERE
            e2.Salary > e1.Salary
                AND e1.DepartmentId = e2.DepartmentId
        )
;