mongodb - 使用 Mongo 驱动程序的 Azure CosmosDB : Get Count With out getting all documents based on element in sub sub document in C#.Net

Question

下面是我存储在 Azure MongoDB 中的 JSON 结构(粘贴示例结构)，我想使用 Plyrs 中存在的 userID 元素进行查询( Sub Sub 文档)来获取用户参加过的所有锦标赛的列表。

1. 我尝试过 Aggregate() 但没有成功。请纠正我如果我遗漏了一些东西，下面是它的代码。

2. 尝试使用构建器但没有成功，使用构建器我可以检索最多一个级别(子集合，带有 json(粘贴在下面)引用最多 tbls )我可以通过任何方式查询 Plyrs(子子集合)。

3. Azure MongoDB 是否支持 Aggregate() 或在不获取整个文档的情况下进行计数？

请指导我聚合

   var count = sampleMongoDataBase.GetCollection<GameInfo>(sampleCollectionName).Aggregate()
                    .Unwind<GameInfo, TableDocumet>(t => t.Tables)
                    .Unwind<TableDocumet, PlayerDocument>(p => p.Players)
                   .Match(x => x.UserID == "3fd30fa8-f5c5-4311-8741-4032142bbb33")
                   .Group(new MongoDB.Bson.BsonDocument { { "id", "$Plyrs._id" }, { "count", new MongoDB.Bson.BsonDocument("$sum", 1) } }); 

build 者

 mongoDataBase.GetCollection<GameInfo>(mongoCollectionName).Find(Builders<GameInfo>.Filter.ElemMatch(x => x.Tables,t => t.TableId == 1)).Count();

错误:命令聚合失败:不支持“$group”。

JSON:

`

{
"TnId": 651,
"QnId": "7a5de5dc-b02f-4013-9d02-ebf8430e7a56",
"samt": 10,
"tbls": [
  {
    "TblId": 1,
    "Plyrs": [
      {
        "_id": 1048995,
        "UserId": "FC381A6D717B6973-711BD743AE90E6D7",
        "St": 3,
        "PCS": 2,
        "ConnId": null,
        "DN": "Roman Yates",
        "RB": 2,
        "LL": 1,
        "Chips": 5000,
        "Rank": 46,
        "ExitLvl": 0,
        "TRA": 0,
        "PRI": "",
        "IsAns": false
      },
      {
        "_id": 1048996,
        "UserId": "fc3e0971-2c3c-e697-b68a-33b12a207bc2",
        "St": 3,
        "PCS": 2,
        "ConnId": null,
        "DN": "Neil Gaines",
        "RB": 2,
        "LL": 1,
        "Chips": 5000,
        "Rank": 46,
        "ExitLvl": 0,
        "TRA": 0,
        "PRI": "",
        "IsAns": false
      },
      {
        "_id": 1048997,
        "UserId": "FC369812-6DC04066-A133-1C10EEBA1546",
        "St": 3,
        "PCS": 2,
        "ConnId": null,
        "DN": "Lori Reyes",
        "RB": 2,
        "LL": 1,
        "Chips": 5000,
        "Rank": 46,
        "ExitLvl": 0,
        "TRA": 0,
        "PRI": "",
        "IsAns": false
      },
      {
        "_id": 1048998,
        "UserId": "FC2AC461-C7FAD800D3D79A2CD2680C72",
        "St": 3,
        "PCS": 2,
        "ConnId": null,
        "DN": "Duane Hoffman",
        "RB": 2,
        "LL": 1,
        "Chips": 5000,
        "Rank": 46,
        "ExitLvl": 0,
        "TRA": 0,
        "PRI": "",
        "IsAns": false
      },
      {
        "_id": 1048999,
        "UserId": "FC39AFCF-688C-B61A-A0DB-80EADAC832CD",
        "St": 3,
        "PCS": 2,
        "ConnId": null,
        "DN": "Alfredo Ware",
        "RB": 2,
        "LL": 1,
        "Chips": 5000,
        "Rank": 46,
        "ExitLvl": 0,
        "TRA": 0,
        "PRI": "",
        "IsAns": false
      },
      {
        "_id": 1049000,
        "UserId": "FC2B863D-9ACC-13C706EA-8E31917566DB",
        "St": 3,
        "PCS": 2,
        "ConnId": null,
        "DN": "Abigail Riddle",
        "RB": 2,
        "LL": 1,
        "Chips": 5000,
        "Rank": 46,
        "ExitLvl": 0,
        "TRA": 0,
        "PRI": "",
        "IsAns": false
      }
    ]
  },
  {
    "TblId": 2,
    "Plyrs": [
      {
        "_id": 1049001,
        "UserId": "FC2BCC93-DDAE-4622-8D1226BDF1181D63",
        "St": 3,
        "PCS": 2,
        "ConnId": null,
        "DN": "Rene Spence",
        "RB": 2,
        "LL": 1,
        "Chips": 5000,
        "Rank": 46,
        "ExitLvl": 0,
        "TRA": 0,
        "PRI": "",
        "IsAns": false
      },
      {
        "_id": 1049002,
        "UserId": "FC3D0CF42017-C3BFF460-E8DBDE3D1D77",
        "St": 3,
        "PCS": 2,
        "ConnId": null,
        "DN": "TU006918",
        "RB": 2,
        "LL": 1,
        "Chips": 5000,
        "Rank": 46,
        "ExitLvl": 0,
        "TRA": 0,
        "PRI": "",
        "IsAns": false
      },
      {
        "_id": 1049003,
        "UserId": "FC2CDE495F34E557-77C8-4B10981B7758",
        "St": 3,
        "PCS": 2,
        "ConnId": null,
        "DN": "Marshall Lutz",
        "RB": 2,
        "LL": 1,
        "Chips": 5000,
        "Rank": 46,
        "ExitLvl": 0,
        "TRA": 0,
        "PRI": "",
        "IsAns": false
      },
      {
        "_id": 1049004,
        "UserId": "FC3EE1FDB4913FF345AE90CD14BE3607",
        "St": 3,
        "PCS": 2,
        "ConnId": null,
        "DN": "Roberto Burton",
        "RB": 2,
        "LL": 1,
        "Chips": 5000,
        "Rank": 46,
        "ExitLvl": 0,
        "TRA": 0,
        "PRI": "",
        "IsAns": false
      },
      {
        "_id": 1049005,
        "UserId": "FC378E3C-C2A0528F094A-7FB31BD9D278",
        "St": 3,
        "PCS": 2,
        "ConnId": null,
        "DN": "Summer Stephenson",
        "RB": 2,
        "LL": 1,
        "Chips": 5000,
        "Rank": 46,
        "ExitLvl": 0,
        "TRA": 0,
        "PRI": "",
        "IsAns": false
      },
      {
        "_id": 1049006,
        "UserId": "FC431BBB-A79D45A0EAB034676C755E5A",
        "St": 3,
        "PCS": 2,
        "ConnId": null,
        "DN": "Terence Fischer",
        "RB": 2,
        "LL": 1,
        "Chips": 5000,
        "Rank": 46,
        "ExitLvl": 0,
        "TRA": 0,
        "PRI": "",
        "IsAns": false
      }
    ]
  }

输出:例如，计数:5

Answer 1

并非所有 MongoDB 查询功能都出现在 Cosmos MongoDB API 中，目前聚合管道是尚未实现的功能之一。这就是为什么您收到错误消息，指出不支持 $group。

EDIT - As of November 2017, Aggregation Pipeline is now a supported operation with the MongoDB API of Cosmos DB. Full list of supported features is here.

不久前，DocumentDB API 中添加了常规聚合(sum、min、max、avg、count)。

目前，您必须在 MongoDB API 中进行自己的聚合。

注意:支持 count()，因此假设您过滤数据(没有聚合管道)，您可以执行以下操作:

db.collection.find({...}).count()

同样，您可以通过排序执行 $min 或 $max 。因此，对于 $max，您可以执行以下操作来查找 foo 的最大值:

db.collection.find({...},{foo:1}).sort({foo:-1}).limit(1)