MySQL Cookbook, 2nd Edition

Starting a Sequence at a Particular Value

Problem

Sequences start at 1, but you want to use a different starting value.

Solution

Add an AUTO_INCREMENT clause to your CREATE TABLE statement when you create the table. If the table has already been created, use an ALTER TABLE statement to set the starting value.

Discussion

By default, AUTO_INCREMENT sequences start at one:

mysql>CREATE TABLE t
    -> (id INT UNSIGNED NOT NULL AUTO_INCREMENT, PRIMARY KEY (id));
mysql> INSERT INTO t (id) VALUES(NULL);
mysql> INSERT INTO t (id) VALUES(NULL);
mysql> INSERT INTO t (id) VALUES(NULL);
mysql> SELECT id FROM t ORDER BY id;
+----+
| id |
+----+
|  1 |
|  2 |
|  3 |
+----+

For MyISAM or InnoDB tables, you can begin the sequence at a specific initial value n by including an AUTO_INCREMENT = n clause at the end of the CREATE TABLE statement:

mysql>CREATE TABLE t
    -> (id INT UNSIGNED NOT NULL AUTO_INCREMENT, PRIMARY KEY (id))
    -> AUTO_INCREMENT = 100;
mysql> INSERT INTO t (id) VALUES(NULL);
mysql> INSERT INTO t (id) VALUES(NULL);
mysql> INSERT INTO t (id) VALUES(NULL);
mysql> SELECT id FROM t ORDER BY id;
+-----+
| id  |
+-----+
| 100 |
| 101 |
| 102 |
+-----+

Alternatively, you can create the table and then set the initial sequence value with ALTER TABLE:

mysql>CREATE TABLE t
    -> (id INT UNSIGNED NOT NULL AUTO_INCREMENT, PRIMARY KEY (id));
mysql> ALTER TABLE t AUTO_INCREMENT = 100;
mysql> INSERT INTO t (id) VALUES(NULL);
mysql> INSERT INTO t (id) VALUES(NULL);
mysql> INSERT INTO t (id) VALUES(NULL);
mysql> SELECT id ...