mysql> CREATE TABLE test_innodb(
    ->    id INT UNSIGNED AUTO_INCREMENT KEY,
    ->    username VARCHAR(20) NOT NULL
    ->  );
Query OK, 0 rows affected (0.47 sec)

mysql> show create table test_innodb;
+-------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table       | Create Table                                                                                                                                                               |
+-------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| test_innodb | CREATE TABLE `test_innodb` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `username` varchar(20) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 |
+-------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

为什么我的存储引擎还是MyISAM