Yii:如何在使用activerecord时对特定查询使用不同的数据库

'components' => [
    'db' => [
        'class' => 'yii\db\Connection',
        'dsn' => 'mysql:host=localhost;dbname=mydatabase',
        'username' => 'root',
        'password' => 'password',
        'charset' => 'utf8',
    ],
    'db2' => [
        'class' => 'yii\db\Connection',
        'dsn' => 'mysql:host=localhost;dbname=mydatabase2',
        'username' => 'root',
        'password' => 'password',
        'charset' => 'utf8',
    ],
],

$users = User::find()->all(); // 使用默认的数据库连接

$users2 = User::find()->db('db2')->all(); // 使用名为db2的数据库连接