PHP mongodb总和查询

Question

MongoDB can not get the total.

MYSQL :

select sum(play) as toplam from videos

MongoDB :

    $group = $naytu->db->videos->group(array(), array("toplam" => 0), "function(obj, prev) {prev.toplam = prev.toplam + obj.play - 0;}"); 

results (print_r)

Array
(
[retval] => Array
    (
        [0] => Array
            (
                [toplam] => NAN
            )

    )

[count] => 78656
[keys] => 1
[ok] => 1
)

where is the problem ?

Answer 1

In PHP @Neils answer is:

$mongo->videos->aggregate([
    ['$group' => ['_id' => null, 'toplam' => ['$sum' => '$play']]]
]);