mysql>
mysql> CREATE TABLE employee (
-> grp ENUM('A','B','C') NOT NULL,
-> id MEDIUMINT NOT NULL AUTO_INCREMENT,
-> name CHAR(30) NOT NULL,
-> PRIMARY KEY (grp,id)
-> );
Query OK, 0 rows affected (0.02 sec)
mysql>
mysql> INSERT INTO employee (grp,name) VALUES ('A','A1'),
-> ('B','B1'),
-> ('C','C1'),
-> ('A','A2'),
-> ('B','B2'),
-> ('C','C2');
Query OK, 6 rows affected (0.00 sec)
Records: 6 Duplicates: 0 Warnings: 0
mysql>
mysql> SELECT * FROM employee ORDER BY grp,id;
+-----+----+------+
| grp | id | name |
+-----+----+------+
| A | 1 | A1 |
| A | 2 | A2 |
| B | 1 | B1 |
| B | 2 | B2 |
| C | 1 | C1 |
| C | 2 | C2 |
+-----+----+------+
6 rows in set (0.00 sec)
mysql>
mysql> drop table employee;
Query OK, 0 rows affected (0.00 sec)
mysql>