_1270.sql

--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