It gives an error getting a HAS_MANY connection from the model (Invalid argument supplied for foreach()), how to fix it?

Question

Yii

Actually, code:
Model:

public function relations()
  {
    return array(
      'server' => array(self::MANY_MANY, 'AmxServerinfo', 'amx_admins_servers(admin_id, server_id)'),
      'admin_server' => array(self::HAS_MANY, 'AmxAdminsServers', 'admin_id'),
    );
  }

Controller:

$model=Amxadmins::model()->findByPk($id);
var_dump($model->admin_server);

Mistake:

Answer 1

It's some kind of magic.
I struggled with the problem for 2 days, as soon as I asked - I immediately decided.
The problem was that the related table did not have a primary key. I overridden the primaryKey() method in the associated model and everything worked:

public function primaryKey()
  {
    //return 'id';
    // Для составного первичного ключа следует использовать массив:
    return array('admin_id', 'server_id');
  }