MongoDBの合計を配列のデータに従って集計する方法

Question

私は、フォーム内のデータを持っている：

{ 
    "_id": 1, 
    "array": [{ 
     "who": "jon", 
     "whom": "max", 
     "point": 2, 
     "description": "la-la" 
    }] 
} { 
    "_id": 2, 
    "array": [{ 
     "Id": "jon", 
     "ToId": "peter", 
     "point": 3, 
     "description": "la-la" 
    }] 
} { 
    "_id": 3, 
    "array": [{ 
     "Id": "peter", 
     "ToId": "max", 
     "point": 2, 
     "description": "la-la" 
    }] 
} { 
    "_id": 4, 
    "array": [{ 
     "Id": "max", 
     "ToId": "peter", 
     "point": 3, 
     "description": "la-la" 
    }] 
} 

私はarrayコマンドからデータを取った：形式のデータ

{"ToId" : "peter", "pointCount" : 6} 
{"ToId" : "max", "pointCount" : 4} 

を取得する方法

db.game.aggregate([{$project: {_id: false, array: true}}, {$unwind: "$array"}]) 

{ "array" : { "Id" : "jon", "ToId" : "max", "pointCount" : 2, "description" : "la-la" } } 
{ "array" : { "Id" : "jon", "ToId" : "peter", "pointCount" : 3, "description" : "la-la" } } 
{ "array" : { "Id" : "peter", "ToId" : "max", "pointCount" : 2, "description" : "la-la" } } 
{ "array" : { "Id" : "max", "ToId" : "peter", "pointCount" : 3, "description" : "la-la" } } 

ありがとうございました。

Answer 1

arrayコマンドのデータは入力とは異なります。入力があれば、次のクエリが機能します。

db.game.aggregate([ 
{$unwind: "$array"}, 
{$group:{"_id" : "$array.ToId", "pointCount": {$sum:"$array.point"}}}, 
{$project: {_id: 0, "ToId":"$_id", "pointCount": 1}} 
])