Employees Whose Manager Left the Company

Task: Find the IDs of the employees whose salary is strictly less than $30000 and whose manager left the company. When a manager leaves, their information is deleted.

Table: Employees

+-------------+-------------+
| Column Name | Type        |
+-------------+-------------+
| employee_id | INT         |
| name        | varchar(20) |
| manager_id  | INT         |
| salary      | INT         |
+-------------+-------------+

Input: Employees table:

+-------------+-----------+------------+--------+
| employee_id | name      | manager_id | salary |
+-------------+-----------+------------+--------+
| 3           | Mila      | 9          | 60301  |
| 12          | Antonella | null       | 31000  |
| 13          | Emery     | null       | 67084  |
| 1           | Kalel     | 11         | 21241  |
| 9           | Mikaela   | null       | 50937  |
| 11          | Joziah    | 6          | 28485  |
+-------------+-----------+------------+--------+

Output:

+-------------+
| employee_id |
+-------------+
| 11          |
+-------------+