MariaDB 10.2

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CREATE TABLE users (
  id INT,
  username VARCHAR(30),
  creatorid INT
);
INSERT INTO users VALUES 
(1, 'supUser', null),
(2, '小明', 1),
(3, '小黃', 2),
(4, '小白', 1);
SELECT u.username, c.username
FROM users AS u
INNER JOIN users AS c
WHERE c.id = u.creatorid
ORDER BY u.id ASC;


username
username


小明
supUser

小黃
小明

小白
supUser