Employees and Their Managers - Medium SQL Joins Interview Problem

Problem

Everyone's in the same table — employees and managers alike. Your job is to pair each person with their direct manager. Using the employees table, return each employee's name alongside their manager's name. Employees at the top of the org chart should still appear, with NULL for the manager.

Schema

employees

column	type
id	INTEGER
name	TEXT
manager_id	INTEGER

manager_id references another row's id in the same table; it is NULL for employees with no manager.

Sample Input

id	name	manager_id
1	Alice	NULL
2	Bob	1
3	Carol	1
4	Dave	2
5	Eve	2
6	Frank	3

Sample Output

employee	manager
Alice	NULL
Bob	Alice
Carol	Alice
Dave	Bob
Eve	Bob
Frank	Carol

Alice has no manager — she is the root of the hierarchy. Bob and Carol both report to Alice. Dave and Eve report to Bob. Frank reports to Carol.

Hints