数据库with联合查询后怎么处理$orders [ 2.0 版本 ]

// 先执行sql: SELECT * FROM customer LIMIT 100;
// SELECT * FROM orders WHERE customer_id IN (1,2,...)
$customers = Customer::find()->limit(100)
->with('orders')->all();
foreach ($customers as $customer) {
// 在这个循环的时候就不会再执行sql了
$orders = $customer->orders;
// ...handle $orders...
}

照着文档里这么做，然后获取到的$orders是一个对象，如下：

yii\db\ActiveQuery Object
(
    [sql] => 
    [on] => 
    [joinWith] => 
    [select] => 
    [selectOption] => 
    [distinct] => 
    [from] => 
    [groupBy] => 
    [join] => 
    [having] => 
    [union] => 
    [params] => Array
        (
        )

    [_events:yii\base\Component:private] => Array
        (
        )

    [_behaviors:yii\base\Component:private] => Array
        (
        )

    [where] => 
    [limit] => 
    [offset] => 
    [orderBy] => 
    [indexBy] => 
    [modelClass] => common\models\AuthAssignment
    [with] => 
    [asArray] => 
    [multiple] => 
    [primaryModel] => common\models\Admin Object
        (
            [_attributes:yii\db\BaseActiveRecord:private] => Array
                (
                    [id] => 6
                    [username] => admin
                    [password_hash] => $2y$13$oYZrIQgTsipWdcNMKWCf8uxOIS286hOif9VWxf7.xnQ31MBje5AtS
                    [auth_key] => GQF9VeroKHrdo_72dzEF6SheBBOG-cuR
                    [status] => 1
                    [created_at] => 0
                    [last_time] => 1452569448
                    [ip] => 127.0.0.1
                )

            [_oldAttributes:yii\db\BaseActiveRecord:private] => Array
                (
                    [id] => 6
                    [username] => admin
                    [password_hash] => $2y$13$oYZrIQgTsipWdcNMKWCf8uxOIS286hOif9VWxf7.xnQ31MBje5AtS
                    [auth_key] => GQF9VeroKHrdo_72dzEF6SheBBOG-cuR
                    [status] => 1
                    [created_at] => 0
                    [last_time] => 1452569448
                    [ip] => 127.0.0.1
                )

            [_related:yii\db\BaseActiveRecord:private] => Array
                (
                    [authitem] => 
                )

            [_errors:yii\base\Model:private] => 
            [_validators:yii\base\Model:private] => 
            [_scenario:yii\base\Model:private] => default
            [_events:yii\base\Component:private] => Array
                (
                    [beforeInsert] => Array
                        (
                            [0] => Array
                                (
                                    [0] => Array
                                        (
                                            [0] => yii\behaviors\TimestampBehavior Object
                                                (
                                                    [createdAtAttribute] => created_at
                                                    [updatedAtAttribute] => updated_at
                                                    [value] => 
                                                    [attributes] => Array
                                                        (
                                                            [beforeInsert] => Array
                                                                (
                                                                    [0] => created_at
                                                                    [1] => updated_at
                                                                )

                                                            [beforeUpdate] => updated_at
                                                        )

                                                    [owner] => common\models\Admin Object
 *RECURSION*
                                                )

                                            [1] => evaluateAttributes
                                        )

                                    [1] => 
                                )

                        )

                    [beforeUpdate] => Array
                        (
                            [0] => Array
                                (
                                    [0] => Array
                                        (
                                            [0] => yii\behaviors\TimestampBehavior Object
                                                (
                                                    [createdAtAttribute] => created_at
                                                    [updatedAtAttribute] => updated_at
                                                    [value] => 
                                                    [attributes] => Array
                                                        (
                                                            [beforeInsert] => Array
                                                                (
                                                                    [0] => created_at
                                                                    [1] => updated_at
                                                                )

                                                            [beforeUpdate] => updated_at
                                                        )

                                                    [owner] => common\models\Admin Object
 *RECURSION*
                                                )

                                            [1] => evaluateAttributes
                                        )

                                    [1] => 
                                )

                        )

                )

            [_behaviors:yii\base\Component:private] => Array
                (
                    [0] => yii\behaviors\TimestampBehavior Object
                        (
                            [createdAtAttribute] => created_at
                            [updatedAtAttribute] => updated_at
                            [value] => 
                            [attributes] => Array
                                (
                                    [beforeInsert] => Array
                                        (
                                            [0] => created_at
                                            [1] => updated_at
                                        )

                                    [beforeUpdate] => updated_at
                                )

                            [owner] => common\models\Admin Object
 *RECURSION*
                        )

                )

        )

    [link] => Array
        (
            [item_name] => id
        )

    [via] => 
    [inverseOf] => 
)

我要怎么处理这个对象，以获取我两个数据表数据的集合，初学者求教