标签: 10gen-csharp-driver

认为这将是非常直接的,但我的价值保持不变(0).

我想做的是当用户收到他们没有读过的消息时递增我的UnreadMessages字段,然后在他们有时删除它.所以我认为像这样的代码会起作用:

var userHelper = new MongoHelper<User>();
//increment
userHelper.Collection.Update(Query.EQ("Id", userId.ToId()), Update.Inc("UnreadMessages", 1));
//decrement
userHelper.Collection.Update(Query.EQ("Id", userId.ToId()), Update.Inc("UnreadMessages", -1));

运行后,不会抛出任何错误,但值也不会改变.不,我不是一个接一个地运行,因为上面的代码可以被解释:)

更新

这是我的帮助类:

public class MongoHelper<T> : Sandbox.Services.IMongoHelper<T> where T : class
{
    public MongoCollection<T> Collection { get; private set; }

    public MongoHelper()
    {
        var con = new MongoConnectionStringBuilder(ConfigurationManager.ConnectionStrings["MongoDB"].ConnectionString);
        var server = MongoServer.Create(con);
        var db = server.GetDatabase(con.DatabaseName);
        Collection = db.GetCollection<T>(typeof(T).Name.ToLower());
    }
}

感谢特拉维斯的回答我能够解决这个问题:

MongoHelper<UserDocument> userHelper = new MongoHelper<UserDocument>();
            var user = userHelper.Collection.FindAndModify(Query.EQ("Username", "a"), SortBy.Null, Update.Inc("MessageCount", 1), true).GetModifiedDocumentAs<UserDocument>();

我在10gen Mongo C#驱动程序的v2中使用了新的Fluent Aggregation Pipeline,但在尝试按多个字段分组时遇到异常(下面的示例代码).

抛出的异常是......

命令聚合失败:异常:必须将组聚合字段"Month"定义为对象内的表达式.

我可以通过为我的组密钥创建一个类型来使用它,但是我更喜欢使用匿名类型,因为我需要创建的类型不会用于其他目的.

var agg = db.GetCollection<Order>("orders").Aggregate();

var project = agg.Project(o => new {o.Value
                                  , o.Product
                                  , Month = o.Date.Month
                                  , Year = o.Date.Year});

var group = project.Group(
  key => new { key.Month, key.Product},
  g => new OrderSummary {Month = g.Key.Month
                        ,Product = g.Key.Product
                        , TotalSales = g.Sum(o => o.Value)});

var result =  group.ToListAsync().Result;

以供参考 ...

public class Order : Entity
{

    public DateTime Date { get; set; }

    public string Product { get; set; …

我有以下结构:

public class ThreadDocument
{
    public ThreadDocument()
    {
        Messages = new List<Message>();
        Recipients = new List<Recipient>();
    }

    [JsonIgnore]
    public ObjectId Id { get; set; }
    public IList<Recipient> Recipients { get; set; }
    public IList<Message> Messages { get; set; }
    public DateTime LastMessageSent { get; set; }
    public string LastSentByUserName { get; set; }
    public string LastSentAvatarUrl { get; set; }
    public string Snippet { get; set; }
    public int MessageCount { get; set; }

}

public class Recipient
{
    public …

我试图通过ASP.NET MVC 4中内置的REST api退出MongoDB集合中的所有文档,当我输入localhost时遇到错误:50491/api/document:

反序列化类Acord_Rest_API.Models.Document的Id属性时发生错误:无法从BsonType ObjectId反序列化字符串.

我的控制器看起来像:

public class DocumentController : ApiController
{
    public readonly MongoConnectionHelper<Document> docs;

    public DocumentController()
    {
        docs = new MongoConnectionHelper<Document>();
    }

    public IList<Document> getAllDocs()
    {
        var alldocs = docs.collection.FindAll();
        return alldocs.ToList();
    }
}

我的MongoDB文档是这样的吗？

我在这里错过了什么？

我连接到DB的类:

public class MongoConnectionHelper<T> where T: class
{
    public MongoCollection<T> collection { get; private set; }

    public MongoConnectionHelper()
    {
        string connectionString = "mongodb://127.0.0.1";
        var server = MongoServer.Create(connectionString);
        if (server.State == MongoServerState.Disconnected)
        {
            server.Connect();
        }
        var conn = server.GetDatabase("Acord");
        collection = conn.GetCollection<T>("Mappings"); …

我使用c#和asp.net mvc(visual studio 2015).当我尝试将mongodb连接到c#时,会出现此错误:

MongoDB.Driver.MongoConfigurationException: The connection string 'mongodb:://localhost' is not valid.

和错误来源是:

var client = new MongoClient(Settings.Default.bigdataconexionstrin);

这是我的代码:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web.Mvc;
using WebApplication5.Properties;
using MongoDB.Driver;
using MongoDB.Driver.Linq;

namespace WebApplication5.Controllers
{
    [Authorize]
    public class HomeController : Controller
    {
        public IMongoDatabase db1;
        public HomeController()
        {
            var client = new MongoClient(Settings.Default.bigdataconexionstrin);
            MongoClientSettings settings = new MongoClientSettings();
            settings.Server = new MongoServerAddress("localhost", 27017);
            this.db1 = client.GetDatabase(Settings.Default.db);
        }

        public ActionResult Index()
        {
            return View();
        }
    }
}