refactor 1270

Author: fishercoder1534

database/_1270.sql

@@ -1,57 +1,2 @@
---1270. All People Report to the Given Manager
---
---Table: Employees
---
---+---------------+---------+
---| Column Name   | Type    |
---+---------------+---------+
---| employee_id   | int     |
---| employee_name | varchar |
---| manager_id    | int     |
---+---------------+---------+
---employee_id is the primary key for this table.
---Each row of this table indicates that the employee with ID employee_id and name employee_name reports his work to his/her direct manager with manager_id
---The head of the company is the employee with employee_id = 1.
---
---
---Write an SQL query to find employee_id of all employees that directly or indirectly report their work to the head of the company.
---
---The indirect relation between managers will not exceed 3 managers as the company is small.
---
---Return result table in any order without duplicates.
---
---The query result format is in the following example:
---
---Employees table:
---+-------------+---------------+------------+
---| employee_id | employee_name | manager_id |
---+-------------+---------------+------------+
---| 1           | Boss          | 1          |
---| 3           | Alice         | 3          |
---| 2           | Bob           | 1          |
---| 4           | Daniel        | 2          |
---| 7           | Luis          | 4          |
---| 8           | Jhon          | 3          |
---| 9           | Angela        | 8          |
---| 77          | Robert        | 1          |
---+-------------+---------------+------------+
---
---Result table:
---+-------------+
---| employee_id |
---+-------------+
---| 2           |
---| 77          |
---| 4           |
---| 7           |
---+-------------+
---
---The head of the company is the employee with employee_id 1.
---The employees with employee_id 2 and 77 report their work directly to the head of the company.
---The employee with employee_id 4 report his work indirectly to the head of the company 4 --> 2 --> 1.
---The employee with employee_id 7 report his work indirectly to the head of the company 7 --> 4 --> 2 --> 1.
---The employees with employee_id 3, 8 and 9 don't report their work to head of company directly or indirectly.
-
---# Write your MySQL query statement below
 select e3.employee_id from Employees e1, Employees e2, Employees e3
 where e1.manager_id = 1 and e2.manager_id = e1.employee_id and e3.manager_id = e2.employee_id and e3.employee_id != 1