按列名选择

CREATE TABLE stack(
    id INT,
    username VARCHAR(30) NOT NULL,
    password VARCHAR(30) NOT NULL
);

INSERT INTO stack (`id`, `username`, `password`) VALUES (1, 'Foo', 'hiddenGem');
INSERT INTO stack (`id`, `username`, `password`) VALUES (2, 'Baa', 'verySecret');

询问

SELECT id FROM stack;

结果

+------+
| `id`   |
+------+
|    1 |
|    2 |
+------+