Find Low-Paid Employees Whose Recorded Manager Row Is Gone
Company: Amazon
Role: Software Engineer
Category: Data Manipulation (SQL/Python)
Difficulty: easy
Interview Round: Other
### Problem
Return employee_id for employees paid strictly less than 30000 whose non-NULL manager_id no longer identifies any Employees row. A NULL manager_id means no manager, not a manager who left. Sort employee_id ascending.
### Tables
Table: `Employees`
```text
+-------------+----------+
| Column Name | Type |
+-------------+----------+
| employee_id | int |
| name | varchar |
| manager_id | int |
| salary | int |
+-------------+----------+
In SQL, employee_id is the primary key for this table.
This table contains information about the employees, their salary, and the ID of their manager. Some employees do not have a manager (manager_id is null).
```
### Example
```text
Employees (employee_id,name,manager_id,salary): (1,Ada,9,29999), (2,Bo,NULL,20000), (3,Cam,4,25000), (4,Dee,NULL,50000), (5,Eli,8,30000)
Output (employee_id): (1)
```
### What a Strong Answer Covers
- Apply the strict salary cutoff and require a recorded manager ID.
- Return employees whose recorded manager is absent and sort the requested IDs.
### Follow-up Questions
- How would you report employees whose manager exists but is marked inactive?
- How would you identify the missing manager IDs with the most affected employees?
Overview: Find low-paid employees whose recorded manager ID no longer identifies an employee, and return their IDs in order.
