C# mongodb帮助类

这是在C#连接MongoDB的帮助类，所使用的驱动是在Vs2015的Nuget管理器中下载的mongodb驱动。

下载第一个，会自动下载下面的两个，不要删除。

在配置文件中配置连接字符串connStr和数据库名称dbName：

 <appSettings>
     <add key="webpages:Version" value="3.0.0.0"/>
     <add key="webpages:Enabled" value="false"/>
     <add key="ClientValidationEnabled" value="true"/>
     <add key="UnobtrusiveJavaScriptEnabled" value="true"/>
     <add key="dbName" value="demodb"/>
 </appSettings>
 <connectionStrings>
     <add name="connStr" connectionString="mongodb://127.0.0.1:27017"/>
 </connectionStrings>

MongoDbHelper类：

 using Cong.Model;
 using MongoDB.Bson;
 using MongoDB.Driver;
 using System;
 using System.Collections.Generic;
 using System.Configuration;
 using System.Linq;

 namespace Cong.Utility
 {
     public class Db
     {
         private static readonly string connStr = ConfigurationManager.ConnectionStrings["connStr"].ToString();

         private static readonly string dbName = ConfigurationManager.AppSettings["dbName"].ToString();

         private static IMongoDatabase db = null;

         private static readonly object lockHelper = new object();

         private Db() { }

         public static IMongoDatabase GetDb()
         {
             if (db == null)
             {
                 lock (lockHelper)
                 {
                     if (db == null)
                     {
                         var client = new MongoClient(connStr);
                         db = client.GetDatabase(dbName);
                     }
                 }
             }
             return db;
         }
     }

     public class MongoDbHelper<T> where T : BaseEntity
     {
         private IMongoDatabase db = null;

         private IMongoCollection<T> collection = null;

         public MgHelper()
         {
             this.db = Db.GetDb();
             collection = db.GetCollection<T>(typeof(T).Name);
         }

         public T Insert(T entity)
         {
             var flag = ObjectId.GenerateNewId();
             entity.GetType().GetProperty("Id").SetValue(entity, flag);
             entity.State = "y";
             entity.CreateTime = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
             entity.UpdateTime = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");

             collection.InsertOneAsync(entity);
             return entity;
         }

         public void Modify(string id, string field, string value)
         {
             var filter = Builders<T>.Filter.Eq("Id", ObjectId.Parse(id));
             var updated = Builders<T>.Update.Set(field, value);
             UpdateResult result = collection.UpdateOneAsync(filter, updated).Result;
         }

         public void Update(T entity)
         {
             var old = collection.Find(e => e.Id.Equals(entity.Id)).ToList().FirstOrDefault();

             foreach (var prop in entity.GetType().GetProperties())
             {
                 var newValue = prop.GetValue(entity);
                 var oldValue = old.GetType().GetProperty(prop.Name).GetValue(old);
                 if (newValue != null)
                 {
                     if (!newValue.ToString().Equals(oldValue.ToString()))
                     {
                         old.GetType().GetProperty(prop.Name).SetValue(old, newValue.ToString());
                     }
                 }
             }
             old.State = "y";
             old.UpdateTime = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");

             var filter = Builders<T>.Filter.Eq("Id", entity.Id);
             ReplaceOneResult result = collection.ReplaceOneAsync(filter, old).Result;
         }

         public void Delete(T entity)
         {
             var filter = Builders<T>.Filter.Eq("Id", entity.Id);
             collection.DeleteOneAsync(filter);
         }

         public T QueryOne(string id)
         {
             return collection.Find(a => a.Id == ObjectId.Parse(id)).ToList().FirstOrDefault();
         }

         public List<T> QueryAll()
         {
             return collection.Find(a => a.State.Equals("y")).ToList();
         }
     }
 }

另外，我的实体类全部都继承自下面这个基类，里面有几个数据中常用的字段

BaseEntity：

 using MongoDB.Bson;
 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;

 namespace Cong.Model
 {
     public abstract class BaseEntity
     {
         public ObjectId Id { get; set; }

         public string State { get; set; }

         public string CreateTime { get; set; }

         public string UpdateTime { get; set; }
     }
 }

最后，这个是我在MVC的一个控制器的代码，使用了增改查的功能，以供参考，另外这个我是用模板生成的代码。

 using Cong.Model;
 using Cong.Utility;
 using MongoDB.Bson;
 using System.Web.Mvc;
 using WebApp.Models;

 namespace WebApp.Controllers
 {

     public partial class AuthController : BaseController
     {
         MgHelper<Auth> mg = new MgHelper<Auth>();

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

         [HttpGet]
         public ActionResult Create()
         {
             return View();
         }

         [HttpPost]
         public ActionResult Create(Auth auth)
         {
             mg.Insert(auth);
             return Content("<script>alert('success!');window.location='/Auth/Create';</script>");
         }

         [HttpGet]
         public ActionResult Modify()
         {
             AuthVM authvm = new AuthVM { Auths = mg.QueryAll() };
             return View(authvm);
         }

         [HttpPost]
         public ActionResult Modify(Auth auth, FormCollection form)
         {
             auth.Id = ObjectId.Parse(form["id"]);
             mg.Update(auth);
             return Content("<script>alert('success!');window.location='/Auth/Modify';</script>");
         }

         [HttpPost]
         public string Delete(string id)
         {
             mg.Modify(id, "State", "n");
             return "success!";
         }
     }

     public partial class RoleController : BaseController
     {
         MgHelper<Role> mg = new MgHelper<Role>();

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

         [HttpGet]
         public ActionResult Create()
         {
             return View();
         }

         [HttpPost]
         public ActionResult Create(Role role)
         {
             mg.Insert(role);
             return Content("<script>alert('success!');window.location='/Role/Create';</script>");
         }

         [HttpGet]
         public ActionResult Modify()
         {
             RoleVM rolevm = new RoleVM { Roles = mg.QueryAll() };
             return View(rolevm);
         }

         [HttpPost]
         public ActionResult Modify(Role role, FormCollection form)
         {
             role.Id = ObjectId.Parse(form["id"]);
             mg.Update(role);
             return Content("<script>alert('success!');window.location='/Role/Modify';</script>");
         }

         [HttpPost]
         public string Delete(string id)
         {
             mg.Modify(id, "State", "n");
             return "success!";
         }
     }

     public partial class UserController : BaseController
     {
         MgHelper<User> mg = new MgHelper<User>();

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

         [HttpGet]
         public ActionResult Create()
         {
             return View();
         }

         [HttpPost]
         public ActionResult Create(User user)
         {
             mg.Insert(user);
             return Content("<script>alert('success!');window.location='/User/Create';</script>");
         }

         [HttpGet]
         public ActionResult Modify()
         {
             UserVM uservm = new UserVM { Users = mg.QueryAll() };
             return View(uservm);
         }

         [HttpPost]
         public ActionResult Modify(User user, FormCollection form)
         {
             user.Id = ObjectId.Parse(form["id"]);
             mg.Update(user);
             return Content("<script>alert('success!');window.location='/User/Modify';</script>");
         }

         [HttpPost]
         public string Delete(string id)
         {
             mg.Modify(id, "State", "n");
             return "success!";
         }
     }
 }

我的测试项目是用户管理系统，有三个类： User（用户），Role（角色），Auth（权限）。

源代码下载：http://download.csdn.net/detail/cycong108/9737751