php - Sum 在 php mongodb 中不起作用

Question

下面是我的mongodb数据，

{
        "_id" : ObjectId("598be687c54bba05596e347e"),
        "slotid" : "248x300x250xnewdiv",
        "request_id" : "07f811ee-a8e3-4d76-9390-49f613f6bb86",
        "zoneid" : "248",
        "bidder" : "rubicon",
        "cpm" : 0.6,
        "width" : NumberInt("300"),
        "height" : NumberInt("250"),
        "is_win" : NumberInt("1"),
        "is_fail" : NumberInt("0"),
        "reponsetime" : NumberInt("294"),
        "requestdate" : "2017-08-10 04:52:25",
        "responsedate" : "2017-08-10 04:52:26"
    },
    {
        "_id" : ObjectId("598be687c54bba05596e3480"),
        "slotid" : "248x300x250xnewdiv",
        "request_id" : "07f811ee-a8e3-4d76-9390-49f613f6bb86",
        "zoneid" : "247",
        "bidder" : "rubicon",
        "cpm" : 0.6,
        "width" : NumberInt("468"),
        "height" : NumberInt("60"),
        "is_win" : NumberInt("1"),
        "is_fail" : NumberInt("0"),
        "reponsetime" : NumberInt("299"),
        "requestdate" : "2017-08-10 04:52:25",
        "responsedate" : "2017-08-10 04:52:26"
    }

我需要使用 php 从 mongodb 获取数据，下面是我的 php 代码

 $res = array(
            array(
                '$group' => array(
                    "_id" => array("slotid" => '$slotid',"bidder" => '$bidder'),"total" => array('$sum' => '$cpm'),
                    ),
                ),  
        );
        $db = (new MongoDB\Client)->database;
        $resbids = $db->responsebids->aggregate($res);
        foreach($resbids as $res)
        {
        print_r($res);

    }

我需要按 slotid 和 bidder 以及 cpm value 进行分组，该组工作正常但 cpm 始终显示为零，这段代码有什么问题？下面是我的示例结果，

MongoDB\Model\BSONDocument Object
(
    [storage:ArrayObject:private] => Array
        (
            [_id] => MongoDB\Model\BSONDocument Object
                (
                    [storage:ArrayObject:private] => Array
                        (
                            [slotid] => 248x300x250xnewdiv
                            [bidder] => rubicon
                        )

                )

            [total] => 0
        )

)

感谢任何帮助....

Answer 1

您的每千次展示费用为 float 值，您无法通过 $sum 添加 float 值