Write an SQL query that displays each employee’s name along with their manager’s name using a self‑join on the Employee table.

Assuming the Employee table has columns emp_id, emp_name, and manager_id (which references emp_id of the manager), you can join the table to itself:

SELECT e.emp_name      AS employee_name,
       m.emp_name      AS manager_name
FROM   Employee e
LEFT JOIN Employee m
       ON e.manager_id = m.emp_id;

The LEFT JOIN ensures that employees without a manager (e.g., the CEO) still appear with a NULL manager_name. If you want to exclude those rows, use an INNER JOIN instead. The query runs in O(n) time, where n is the number of employees, because it performs a single hash or merge join on the primary key.