mongo $ unwind并单独汇总返回和新访客的第三个值

Question

来自以下文档示例：

{
    "_id" : ObjectId("528e4798bfa9782c078b4662"),
    "query" : {
        "start-date" : ISODate("2013-11-19T00:00:00Z"),
        "end-date" : ISODate("2013-11-20T00:00:00Z"),
        "ids" : "ga:69564270",
        "dimensions" : "ga:visitorType,ga:visitCount",
        "metrics" : [
            "ga:organicSearches"
        ]
    },
    "columnHeaders" : [
        {
            "name" : "ga:visitorType",
            "columnType" : "DIMENSION",
            "dataType" : "STRING"
        },
        {
            "name" : "ga:visitCount",
            "columnType" : "DIMENSION",
            "dataType" : "STRING"
        },
        {
            "name" : "ga:organicSearches",
            "columnType" : "METRIC",
            "dataType" : "INTEGER"
        }
    ],
    "totalsForAllResults" : {
        "ga:organicSearches" : 119
    },
    "rows" : [
        [
            "New Visitor",
            "1",
            100
        ],
        [
            "Returning Visitor",
            "11",
            1
        ],
        [
            "Returning Visitor",
            "2",
            10
        ],
        [
            "New Visitor",
            "3",
            4
        ],
        [
            "Returning Visitor",
            "4",
            1
        ],
        [
            "Returning Visitor",
            "5",
            1
        ],
        [
            "New Visitor",
            "6",
            1
        ],
        [
            "New Visitor",
            "8",
            1
        ]
    ],
    "query_name" : "GA Organic Traffic Metric",
    "profile_id" : 666,
    "retrieve_date" : ISODate("2013-11-21T17:49:12Z")
}

我如何使用mongo聚合框架：

1通过“query.start-date”

对新访问者进行分组和投影：

2要对以下内容进行分组和投影：按“query.start-date”

返回访问者

目前，正如你可以看到“ga：organicSearches”我有两者的总和，但我需要各自类型的访问者，例如“ga：organicSearchesReturningVisitors”和“ga：organicSearchesNewVisitors”。

提前致谢。

Answer 1

只要您可以进行两次聚合，就可以这样做（我假设每个文档代表一天）：

1. 新访客：

   db.visitors.aggregate({$unwind:"$rows"},
       {$match:{"rows.0":"New Visitor"}},
       {$unwind:"$rows"},
       {$match:{"rows":{$type:1}}},
       {$group:{_id:"$query.start-date",newVisitorsSum:{$sum:"$rows"}}});
   
   { "_id" : ISODate("2013-11-19T00:00:00Z"), "newVisitorsSum" : 106 }
   

2. 回访者：

   db.visitors.aggregate({$unwind:"$rows"},
       {$match:{"rows.0":"Returning Visitor"}},
       {$unwind:"$rows"}, 
       {$match:{"rows":{$type:1}}}, 
       {$group:{_id:"$query.start-date",retVisitorsSum:{$sum:"$rows"}}});
   
   { "_id" : ISODate("2013-11-19T00:00:00Z"), "retVisitorsSum" : 13 }