アンワインドアグリゲーションを元に戻す方法は？

Question

コレクションがどのように元の構造にこれを逆にアンワインド

{ "_id" : 1, "item" : "ABC1", "sizes" : "S" } 
{ "_id" : 1, "item" : "ABC1", "sizes" : "M" } 
{ "_id" : 1, "item" : "ABC1", "sizes" : "L" } 

後

{ "_id" : 1, "item" : "ABC1", sizes: [ "S", "M", "L"] } 

だった考えますか？

構造を変更せずにコレクションを取得したいですが、グループ集計を試みましたが、期待したものが得られません。

実は私の問題だった、私は私の入力コレクションがアンワインドとグループ をして実行した後に元のコレクションを取得できませんでした：

{ 
    "journeys" : { 
     "_id" : "8", 
     "originDate" : ISODate("2017-06-27T03:55:00.000Z"), 
     "destinationDate" : ISODate("2017-06-27T08:55:00.000Z"), 


     "dir" : "OUTBOUND", 
     "proposals" : [ 
      { 
       "_id" : "35", 
       "price" : { 
        "posCurrencyPrice" : "SEK 281.00", 
        "defaultCurrencyPrice" : "SEK 281.00" 
       }, 
       " 
       "trainClass" : "1st Class", 
       "trainClassCode" : "FIRST", 

      }, 
      { 
       "_id" : "39", 
       "price" : { 
        "posCurrencyPrice" : "SEK 377.00", 
        "defaultCurrencyPrice" : "SEK 377.00" 
       }, 
       "trainClass" : "2nd Class", 
       "trainClassCode" : "SECOND", 


      }, 

} 


{ 
    "journeys" : { 
     "_id" : "10", 
     "originDate" : ISODate("2017-06-27T04:20:00.000Z"), 
     "destinationDate" : ISODate("2017-06-27T10:50:00.000Z"), 

     "dir" : "OUTBOUND", 
     "proposals" : [ 
      { 
       "_id" : "49", 
       "price" : { 
        "posCurrencyPrice" : "SEK 490.00", 
        "defaultCurrencyPrice" : "SEK 490.00" 
       }, 

       "trainClass" : "1st Class", 
       "trainClassCode" : "FIRST", 



      }, 

    } 
} 

私は私の期待出力が

ある の提案から2番目のクラスをフィルタリングしたいです

{ 
    "journeys" : { 
     "_id" : "8", 
     "originDate" : ISODate("2017-06-27T03:55:00.000Z"), 
     "destinationDate" : ISODate("2017-06-27T08:55:00.000Z"), 


     "dir" : "OUTBOUND", 
     "proposals" : [ 
      { 
       "_id" : "35", 
       "price" : { 
        "posCurrencyPrice" : "SEK 281.00", 
        "defaultCurrencyPrice" : "SEK 281.00" 
       }, 
       " 
       "trainClass" : "1st Class", 
       "trainClassCode" : "FIRST", 

      }, 


} 


{ 
    "journeys" : { 
     "_id" : "10", 
     "originDate" : ISODate("2017-06-27T04:20:00.000Z"), 
     "destinationDate" : ISODate("2017-06-27T10:50:00.000Z"), 

     "dir" : "OUTBOUND", 
     "proposals" : [ 
      { 
       "_id" : "49", 
       "price" : { 
        "posCurrencyPrice" : "SEK 490.00", 
        "defaultCurrencyPrice" : "SEK 490.00" 
       }, 

       "trainClass" : "1st Class", 
       "trainClassCode" : "FIRST", 



      }, 

    } 
} 

は、次のコードを実行し、別のコレクション

db.searchResource.aggregate({ "$match" : { "_id" : ObjectId("5951d7217f4a9810ccca7289")}}, 
{ "$project" : { "_id" : 0 , "journeys" : "$rssSearchResponse.journeys"}} , { "$unwind" : "$journeys"}, 
{ "$unwind" : "$journeys.proposals"},{ "$match" : { "journeys.proposals.trainClass" : "1st Class"}}, 
{$group:{"_id":"$journeys._id","originDate": { "$first": "$journeys.originDate" }, 
"destinationDate": { "$first": "$journeys.destinationDate" }, 


"dir": { "$first": "$journeys.dir" }, 
"proposals":{ "$push" : "$journeys.proposals" }}}) 

結果

出力した：

{ 
     "_id" : "8", 
     "originDate" : ISODate("2017-06-27T03:55:00.000Z"), 
     "destinationDate" : ISODate("2017-06-27T08:55:00.000Z"), 


     "dir" : "OUTBOUND", 
     "proposals" : [ 
      { 
       "_id" : "35", 
       "price" : { 
        "posCurrencyPrice" : "SEK 281.00", 
        "defaultCurrencyPrice" : "SEK 281.00" 
       }, 
       " 
       "trainClass" : "1st Class", 
       "trainClassCode" : "SECOND", 

      }, 






     "_id" : "10", 
     "originDate" : ISODate("2017-06-27T04:20:00.000Z"), 
     "destinationDate" : ISODate("2017-06-27T10:50:00.000Z"), 

     "dir" : "OUTBOUND", 
     "proposals" : [ 
      { 
       "_id" : "49", 
       "price" : { 
        "posCurrencyPrice" : "SEK 490.00", 
        "defaultCurrencyPrice" : "SEK 490.00" 
       }, 

       "trainClass" : "1st Class", 
       "trainClassCode" : "FIRST", 



      }, 


} 

Answer 1

グループは確かにあなたの応答のためのあなたの質問

db.items.aggregate([ 
    {$match: {}}, 
    {$unwind: "$sizes"}, 
    {$group: { 
     _id: "$_id", 
     sizes: {$push: "$sizes"} 
    }} 
])