如何將mongo文檔轉換爲.Net中的鍵值對？

Question

我想用C＃.Net來查詢MongoDB集合。我想根據一些標準過濾集合，然後只投影某些字段，然後將投影轉換爲鍵值對。

我能夠過濾和項目我想要的方式。不過，我想知道是否有構建的方法將投影轉換爲鍵值對？

這裏是我的蒙戈DB文件看起來像

{ 
    "_id" : 32178271832, 
    "url" : "www.somedomain.com", 
    "fileName" : "somefilename.pdf", 
    "isDone" : true, 
    "client" : ObjectId("56g2e67d7gf2208c2dbe33yt"), 
    "startTime" : ISODate("2015-05-23T18:50:11.271Z"), 
    "endTime" : ISODate("2015-05-23T18:52:43.819Z"), 
    "cost" : 30, 
    "taskGroups" : [ 
     { 
      "phase" : "phase1", 
      "name" : "Some Name",  
      "_id" : ObjectId("43r2e46h7er2208c2geh74e5"), 
      "tasks" : [ 
       { 
        "_id" : ObjectId("43r2e46h7er2208c2geh74e5"), 
        "input" : [],     
        "predecessors" : [] 
       } 
      ] 
     }   
    ], 
    "context" : { 
     "startTime" : ISODate("2016-03-23T18:50:11.271Z"), 
     "endTime" : ISODate("2016-03-23T18:52:43.819Z"), 
     "state" : "GA",  
     "PHASE1" : { 
      "hasaccountnumber" : "Yes", 
      "accountnumber" : 1 
      "Child1":{ 
       "Property1": "SomeValue1" 
       "Property2" : "SomeValue2" 
      } 
     }   
    } 
} 

這裏是我的代碼

public static IDictionary<string,string> GetFromMongo() 
    { 
     var collection = _mongodb.GetCollection<BsonDocument>("kunits"); 
     var filterBuilder = Builders<BsonDocument>.Filter; 
     var filter = filterBuilder.Eq<bool>("isDone", true) & filterBuilder.Exists("isTransformed", false); 

     var projection = Builders<BsonDocument>.Projection 
      .Include("client") 
      .Include("url") 
      .Include("fileName") 
      .Include("context"); 

     var document = collection.Find(filter).Project(projection).FirstOrDefault(); 

     IDictionary<string,string> dictionary = ?? 

     return dictionary; 
    } 

反正是有文檔轉換成字典嗎？該文件具有分層結構。

Update2
所以這就是我所做的。但是，如果BsonValue是JSON，我如何遞歸處理？例如在上面的JSON中，context元素具有分層結構，我如何遞歸循環並在字典中添加它的每個字段？

  var document = collection.Find(filter).Project(projection).FirstOrDefault(); 
     var docs = new Dictionary<string, BsonValue>(); 
     foreach (var elm in document.Elements) 
     { 
      //how to recursively process when elm.value is JSON ?? 

      docs.Add(elm.Name, elm.Value); 

     } 

Answer 1

我不相信FirstOrDefault（）在投影上是正確的。有一個ToDictionary方法可以映射你想要什麼：

var document = collection.Find(filter).Project(projection); 
var dictionary = documents.ToEnumerable().ToDictionary(key => key.client, value => value.url); 

一種不同的方法

var docs = new Dictionary<string, BsonDocument>(); 
var result = collection.Find(filter).Project(projection);  
result.ForEachAsync((bsonDoc) => 
{ 
    string name = bsonDoc.GetValue("[Your Dictionary Key]").AsString; 
    if (!docs.ContainsKey(name)) 
    { 
     docs[name] = bsonDoc; 
    } 
}); 

Answer 2

終於得到它BsonValue擁有財產IsBsonDocument。我們可以檢查以確定vaue是JSON還是原始數據類型。然後循環遞歸

public static Dictionary<string, BsonValue> GetFromMongo() 
    { 
     var collection = _mongodb.GetCollection<BsonDocument>("units"); 
     var filterBuilder = Builders<BsonDocument>.Filter; 
     var filter = filterBuilder.Eq<bool>("isDone", true) & filterBuilder.Exists("isTransformed", false); 

     var projection = Builders<BsonDocument>.Projection 
      .Include("client") 
      .Include("url") 
      .Include("fileName") 
      .Include("context"); 

     var document = collection.Find(filter).Project(projection).FirstOrDefault(); 
     var dictionary = new Dictionary<string, BsonValue>(); 
     Recurse(document, dictionary); 
     return dictionary; 
    } 

    private static void Recurse(BsonDocument doc, Dictionary<string, BsonValue> dictionary) 
    { 
     foreach (var elm in doc.Elements) 
     { 
      if (!elm.Value.IsBsonDocument) 
      { 
       if (!dictionary.ContainsKey(elm.Name)) 
       { 
        dictionary.Add(elm.Name, elm.Value); 
       } 
      } 
      else 
      { 
       Recurse((elm.Value as BsonDocument), dictionary); 
      } 
     } 
    }