PHP mongo驱动程序跳过并限制内部对象

Question

你好，我正在为MongoDB使用PHP驱动程序，而MY Array就是这样

stdClass Object

（     [_id] => stdClass对象         （             [$ id] => 58e0af1b9c76847c7e8b4567         ）

[prod_details] => stdClass Object
    (
        [1] => stdClass Object
            (
                [1] => stdClass Object
                    (
                        [prod_id] => 1
                        [asin] => xxxxxx
                        [sku] => 1
                        [prod_name] => Windows 98: Second Edition
                        [prod_price] => 13433
                        [prod_price_f] => 13433
                        [prod_currency] => INR
                        [prod_price_min] => 
                        [prod_price_max] => 
                        [prod_quantity] => 1
                        [prod_condition] => New
                        [prod_shipping] => 60.00
                        [prod_category] => 
                        [prod_added] => 
                    )

                [11] => stdClass Object
                    (
                        [prod_id] => 11
                        [asin] => xxxxxxx
                        [sku] => 11
                        [prod_name] => The Coke Machine: The Dirty Truth Behind the World's Favorite Soft Drink [Paperback] [Sep 06, 2011] Blanding, Michael
                        [prod_price] => 2500
                        [prod_price_f] => 2500
                        [prod_currency] => INR
                        [prod_price_min] => 
                        [prod_price_max] => 
                        [prod_quantity] => 8
                        [prod_condition] => New
                        [prod_shipping] => 60.00
                        [prod_category] => 
                        [prod_added] => 
                    )

                [12] => stdClass Object
                    (
                        [prod_id] => 12
                        [asin] => xxxxxxx
                        [sku] => 12
                        [prod_name] => In Other Words [Hardcover] [Feb 09, 2016] Jhumpa Lahiri
                        [prod_price] => 748.9
                        [prod_price_f] => 748.9
                        [prod_currency] => INR
                        [prod_price_min] => 
                        [prod_price_max] => 
                        [prod_quantity] => 8
                        [prod_condition] => New
                        [prod_shipping] => 60.00
                        [prod_category] => 
                        [prod_added] => 
                    )

当我运行PHP查询时，我得到了所有结果，而没有使用跳过和限制过滤结果

$collection->find(array('_id'=>new MongoId($mongoid)), array('prod_details.1' => ''))->skip(0)->limit(2);

在这里，我遍历prod_details >> 1，并将限制0设置为2，但是我得到了所有对象。并且限制不起作用。

请帮助。