CREATE TABLE employee(
    id INT PRIMARY KEY,
    name VARCHAR(50),
    manager_id INT
);

INSERT INTO employee(id, name, manager_id)
VALUES
(101, "adam", 103),
(102, "bob", 104),
(103, "casey", NULL),
(104, "DONALD", 103);

-- SELECT*FROM employee;

SELECT a.name as manager_name, b.name
FROM employee as a
JOIN employee as b
ON a.id=b.manager_id;