Question

is there a single select statement that will do all three of those: primary key, unique, and auto_increment?

Answer 1

Here we create a little table:

mysql> CREATE TABLE test2 (id int);

Note Null is YES, and id is not a primary key, nor does it auto_increment.

mysql> DESCRIBE test2;
+-------+---------+------+-----+---------+-------+
| Field | Type    | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| id    | int(11) | YES  |     | NULL    |       | 
+-------+---------+------+-----+---------+-------+
1 row in set (0.00 sec)

Here is the alter command:

mysql> ALTER TABLE test2 MODIFY COLUMN id INT NOT NULL auto_increment, ADD primary key (id);

Now Null is NO, and id is a primary key with auto_increment.

mysql> describe test2;
describe test2;
+-------+---------+------+-----+---------+----------------+
| Field | Type    | Null | Key | Default | Extra          |
+-------+---------+------+-----+---------+----------------+
| id    | int(11) | NO   | PRI | NULL    | auto_increment | 
+-------+---------+------+-----+---------+----------------+
1 row in set (0.00 sec)

Primary keys are always unique.