Automatiskt ID nummer (SQL)

3.6.9. Using AUTO_INCREMENT

The AUTO_INCREMENT attribute can be used to generate a unique identity for new rows:
CREATE TABLE animals (
id MEDIUMINT NOT NULL AUTO_INCREMENT,
name CHAR(30) NOT NULL,
PRIMARY KEY (id)
);

INSERT INTO animals (name) VALUES
('dog'),('cat'),('penguin'),
('lax'),('whale'),('ostrich');

SELECT * FROM animals;

Which returns:
+----+---------+
| id | name |
+----+---------+
| 1 | dog |
| 2 | cat |
| 3 | penguin |
| 4 | lax |
| 5 | whale |
| 6 | ostrich |
+----+---------+