MonogDB 2.6相当于group by来获得不同的计数

Question

我的MongoDB查询输出如下：

db.campaign.find({},{"_id":0,"Name":1, "Info.subscriber_id":1})

的产率：

{ "Info" : [ { "subscriber_id" : "" } ], "Name" : "C1" }
{ "Info" : [ { "subscriber_id" : "1" } ], "Name" : "C2" }
{ "Info" : [ { "subscriber_id" : "1" } ], "Name" : "C3" }
{ "Info" : [ { "subscriber_id" : "2" } ], "Name" : "C4" }

我想在MongoDB中找出相同的组中的不同计数：

select subscriber, count(*) totalCount, count(distinct Name) distinctCount 
FROM campaign GROUP BY subscriber;

我已在MongoDB查询下构建，以获得与上述sql查询等效的结果集：

db.campaign.aggregate([
    {"$group":{
        "_id":{
            "subscriber": "$Info.subscriber_id",
            "Name":"$Name"
        },
        "count":{"$sum": 1}
    }},
    {"$group":{
        "_id":{
            "subscriber": "$_id.subscriber"
        },
        "totalCount":{"$sum":"$count"},
        "distinctCount":{"$sum: 1"}
    }}
]);

但是在执行上面的mongodb查询时，我收到的错误如下：

  

2016-05-20T14：50：47.973 + 0530 SyntaxError：意外的令牌}

如果我只从上面的查询中执行第一组，我将获得结果集。

db.campaign.aggregate([
    {"$group":{
        "_id":{
            "subscriber": "$Info.subscriber_id",
            "Name":"$Name"
        },
        "count":{"$sum": 1}
    }}
]);

{ "_id" : { "subscriber" : [ "" ], "Name" : "c1" }, "count" : 1 } 
{ "_id" : { "subscriber" : [ "1" ], "Name" : "c1" }, "count" : 1 } 
{ "_id" : { "subscriber" : [ "1" ], "Name" : "c3" }, "count" : 1 }
{ "_id" : { "subscriber" : [ "2" ], "Name" : "c2" }, "count" : 1 } 
{ "_id" : { "subscriber" : [ "2" ], "Name" : "c4" }, "count" : 1 } 
{ "_id" : { "subscriber" : [ "3" ], "Name" : "c3" }, "count" : 1 }

有人可以让我知道我的查询有什么问题。我使用的是MongoDB2.6。