C#操作Mongodb

因为MongoDb 跨平台，可以免费使用，读写效率高，集群搭建简单，可以水平扩展等各种因素。

我决定研究一下Mongodb,在查看了相关文档后发现它对C#的支持不错，而且还有现成的C#的驱动，

新版的驱动还支持Linq，因为复杂的查询可以交给Linq去实现。正因为官方的驱动很强大。

刚开始接触时发现在大量的东西要去了解，为了能快速处理简单的项目，我对官方驱动做了进一步封装。项目中需要引入官方提供的dll,下载地址

https://github-cloud.s3.amazonaws.com/releases/699689/ea9bea12-819f-11e6-965b-d3b6bb718019.zip?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAISTNZFOVBIJMK3TQ%2F20161218%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20161218T122012Z&X-Amz-Expires=300&X-Amz-Signature=c52d17292deec2a49eb30f53f4847fc168b82df42dfe69252429faad760e8c05&X-Amz-SignedHeaders=host&actor_id=0&response-content-disposition=attachment%3B%20filename%3DCSharpDriver-2.3.0.zip&response-content-type=application%2Foctet-stream

下载好后解压到相应目录，将里面的dll引入到项目下（如红框所示）

以下为我封装的一些简单的增删改查操作

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using MongoDB.Driver;
using MongoDB.Bson;
using MongoDB.Bson.Serialization.Attributes;
using System.Linq.Expressions;

namespace Langu.DbHelper
{
    /// <summary>
    /// MongoDb 数据库操作类
    /// </summary>
    public class MongoHelper<T> where T : BaseEntity
    {
        /// <summary>
        /// 数据库对象
        /// </summary>
        private IMongoDatabase database;
        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="conString">连接字符串</param>
        public MongoHelper(String conString)
        {
            var url = new MongoUrl(conString);
            MongoClientSettings mcs = MongoClientSettings.FromUrl(url);
            mcs.MaxConnectionLifeTime = TimeSpan.FromMilliseconds(1000);
            var client = new MongoClient(mcs);
            this.database = client.GetDatabase(url.DatabaseName);
        }
        /// <summary>
        /// 创建集合对象
        /// </summary>
        /// <param name="collName">集合名称</param>
        ///<returns>集合对象</returns>
        private IMongoCollection<T> GetColletion(String collName)
        {
            return database.GetCollection<T>(collName);
        }

        #region 增加
        /// <summary>
        /// 插入对象
        /// </summary>
        /// <param name="collName">集合名称</param>
        /// <param name="t">插入的对象</param>
        public void Insert(String collName, T t)
        {
            var coll = GetColletion(collName);
            coll.InsertOne(t);
        }
        /// <summary>
        /// 批量插入
        /// </summary>
        /// <param name="collName">集合名称</param>
        /// <param name="ts">要插入的对象集合</param>
        public void InsertBath(String collName, IEnumerable<T> ts)
        {
            var coll = GetColletion(collName);
            coll.InsertMany(ts);
        }
        #endregion

        #region 删除
        /// <summary>
        /// 按BsonDocument条件删除
        /// </summary>
        /// <param name="collName">集合名称</param>
        /// <param name="document">文档</param>
        /// <returns></returns>
        public Int64 Delete(String collName, BsonDocument document)
        {
            var coll = GetColletion(collName);
            var result = coll.DeleteOne(document);
            return result.DeletedCount;
        }
        /// <summary>
        /// 按json字符串删除
        /// </summary>
        /// <param name="collName">集合名称</param>
        /// <param name="json">json字符串</param>
        /// <returns></returns>
        public Int64 Delete(String collName, String json)
        {
            var coll = GetColletion(collName);
            var result = coll.DeleteOne(json);
            return result.DeletedCount;
        }
        /// <summary>
        /// 按条件表达式删除
        /// </summary>
        /// <param name="collName">集合名称</param>
        /// <param name="predicate">条件表达式</param>
        /// <returns></returns>
        public Int64 Delete(String collName, Expression<Func<T, Boolean>> predicate)
        {
            var coll = GetColletion(collName);
            var result = coll.DeleteOne(predicate);
            return result.DeletedCount;
        }
        /// <summary>
        /// 按检索条件删除
        /// 建议用Builders<T>构建复杂的查询条件
        /// </summary>
        /// <param name="collName">集合名称</param>
        /// <param name="filter">条件</param>
        /// <returns></returns>
        public Int64 Delete(String collName, FilterDefinition<T> filter)
        {
            var coll = GetColletion(collName);
            var result = coll.DeleteOne(filter);
            return result.DeletedCount;
        }
        #endregion

        #region 修改
        /// <summary>
        /// 修改文档
        /// </summary>
        /// <param name="collName">集合名称</param>
        /// <param name="filter">修改条件</param>
        /// <param name="update">修改结果</param>
        /// <param name="upsert">是否插入新文档（filter条件满足就更新，否则插入新文档）</param>
        /// <returns></returns>
        public Int64 Update(String collName, Expression<Func<T, Boolean>> filter, UpdateDefinition<T> update, Boolean upsert = false)
        {
            var coll = GetColletion(collName);
            var result = coll.UpdateMany(filter, update, new UpdateOptions { IsUpsert = upsert });
            return result.ModifiedCount;
        }
        /// <summary>
        /// 用新对象替换新文档
        /// </summary>
        /// <param name="collName">集合名称</param>
        /// <param name="filter">修改条件</param>
        /// <param name="t">新对象</param>
        /// <param name="upsert">是否插入新文档（filter条件满足就更新，否则插入新文档）</param>
        /// <returns>修改影响文档数</returns>
        public Int64 Update(String collName, Expression<Func<T, Boolean>> filter, T t, Boolean upsert = false)
        {
            var coll = GetColletion(collName);
            BsonDocument document = t.ToBsonDocument<T>();
            document.Remove("_id");
            UpdateDocument update = new UpdateDocument("$set", document);
            var result = coll.UpdateMany(filter, update, new UpdateOptions { IsUpsert = upsert });
            return result.ModifiedCount;
        }
        #endregion

        /// <summary>
        /// 查询，复杂查询直接用Linq处理
        /// </summary>
        /// <param name="collName">集合名称</param>
        /// <returns>要查询的对象</returns>
        public IQueryable<T> GetQueryable(String collName)
        {
            var coll = GetColletion(collName);
            return coll.AsQueryable<T>();
        }
        #region 查询 
        #endregion
    }

    /// <summary>
    /// 实体基类，方便生成_id
    /// </summary>
    public class BaseEntity
    {
        [BsonRepresentation(BsonType.ObjectId)]
        public String Id { get; set; }
        /// <summary>
        /// 给对象初值
        /// </summary>
        public BaseEntity()
        {
            this.Id = ObjectId.GenerateNewId().ToString();
        }
    }
}

做了一个简单的控制台调用（前提是mongodb服务已经打开,安装Mongodb以及打开部分有时间会一并发上来）

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Langu.DbHelper;
using System.Threading;
using System.Linq.Expressions;
using MongoDB.Driver;

namespace Client
{
    class Program
    {
        static void Main(string[] args)
        {
            //连接字符串 127.0.0.1 服务器IP   27100 mongodb服务端口号   mydb 数据库名称
            String conString = "mongodb://127.0.0.1:27100/mydb";
            //实例化MongoHelper对象（泛型版本），构造函数要求传入连接字符串
            MongoHelper<User> mongoHelper = new MongoHelper<User>(conString);
            //查询集合 user中有多少数据量
            var cnt = mongoHelper.GetQueryable("user").Count();
            Console.WriteLine(cnt);
            Console.ReadKey();
        }
    }

    internal class User : BaseEntity
    {
        public int Age { get; set; }
        public String Name { get; set; }
    }
}