后端：C#操作Mongodb用法笔记

MongoDB 是一个基于分布式文件存储的数据库。由 C++ 语言编写。旨在为 WEB 应用提供可扩展的高性能数据存储解决方案。今天主要给大家介绍一下C#编程语言下Mongodb的用法。开发环境为VS2015示例主要包括数据的增删改查、分页查询、文件存储等功能。有需要的朋友可以一起学习一下。

1、需要引用Mongodb程序集

MongoDB.Bson.dll

MongoDB.Driver.dll

2、创建Mongodb工具类库 MongodbHelper.cs

using MongoDB.Bson;
using MongoDB.Driver;
using MongoDB.Driver.Builders;
using MongoDB.Driver.GridFS;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.IO;
using System.Linq;


namespace MongodbHelper
{
    /// <summary>
    /// MongoDB的基本增删改查
    /// </summary>
    public class MongodbTool
    {
        private readonly MongoDatabase _db;
        //数据库默认地址
        private readonly string host = ConfigurationManager.AppSettings["db_host"];
        //数据库默认名称
        private readonly string db_name = ConfigurationManager.AppSettings["db_name"];
      
        public MongodbTool()
        {
            var client = new MongoClient(host); //ip及端口
            var server = client.GetServer();
            _db = server.GetDatabase(db_name); //数据库名称
        }


        #region 通用增删改查


        /// <summary>
        /// 新增单个实体模型 modifiy by 2020-11-11
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="entity"></param>
        /// <returns>True:成功,False:失败</returns>
        public bool Insert<T>(T entity)
        {
            bool isOk = true;
            try
            {
                BsonDocument doc = entity.ToBsonDocument();
                WriteConcernResult result = this._db.GetCollection(typeof(T).Name).Insert(doc);
                isOk = result.Ok;
            }
            catch (Exception ex)
            {


            }
            return isOk;
        }


        /// <summary>
        /// 新增实体集合模型
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="entity"></param>
        /// <returns>True:成功,False:失败</returns>
        public bool Add<T>(IEnumerable<T> entity)
        {
            bool isOk = true;
            try
            {
                int s = 1;
                IEnumerable<WriteConcernResult> results = this._db.GetCollection(typeof(T).Name).InsertBatch(entity);
                foreach (var item in results)
                {
                    if (item.Ok)
                        isOk = true;
                    else
                        isOk = false;
                }
            }
            catch (Exception ex)
            {


            }
            return isOk;
        }
        /// <summary>
        /// 查询单条数据
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="Field">查询属性字段</param>
        /// <param name="Value">字段值</param>
        /// <returns>返回当前实体</returns>
        public T FindOne<T>(string Field, string Value)
        {
            T oneEntity = default(T);
            try
            {
                FindOneArgs args = new FindOneArgs
                {
                    Query = Query.EQ(Field, Value)
                };
                oneEntity = this._db.GetCollection(typeof(T).Name).FindOneAs<T>(args);
                this._db.GetCollection(typeof(T).Name).FindAs<T>(Query.GTE(Field, Value)).ToList();
            }
            catch (Exception ex)
            {


            }
            return oneEntity;
        }


        /// <summary>
        /// 查询多条数据
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="Field">查询属性字段</param>
        /// <param name="Value">字段值</param>
        /// <returns>返回当前实体集合</returns>
        public List<T> FindMore<T>(string Field, string Value)
        {
            List<T> list = new List<T>();
            try
            {
                list = this._db.GetCollection(typeof(T).Name).FindAs<T>(Query.GTE(Field, Value)).ToList();
            }
            catch (Exception ex)
            {


            }
            return list;
        }


        /// <summary>
        /// 查询文档所有数据
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <returns></returns>
        public List<T> FindAllMore<T>()
        {
            List<T> list = new List<T>();
            try
            {
                list = this._db.GetCollection(typeof(T).Name).FindAllAs<T>().ToList();
            }
            catch (Exception ex)
            {
            }
            return list;
        }


        /// <summary>
        /// 分页查询文档
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="pageIndex">页次</param>
        /// <param name="pageRow">每页显示记录数</param>
        /// <param name="total">总记录数</param>
        /// <returns></returns>
        public List<T> FindMoreForPage<T>(int pageIndex, int pageRow, ref long total)
        {
            List<T> list = new List<T>();
            try
            {
                total = this._db.GetCollection(typeof(T).Name).FindAllAs<T>().Count();    //获取总记录数
                if (pageIndex == 1)
                {
                    list = this._db.GetCollection(typeof(T).Name).FindAllAs<T>().SetLimit(pageRow).ToList();
                }
                else
                {
                    var bd = this._db.GetCollection(typeof(T).Name).FindAll().SetSortOrder("_id:1").SetLimit((pageIndex - 1) * pageRow).Last();   //获取最后一个ID主键
                    var el = bd.GetElement(0);
                    var value = el.Value;
                    list = this._db.GetCollection(typeof(T).Name).FindAs<T>(Query.GT("_id", value)).SetSortOrder("_id:1").SetLimit(pageRow).ToList();


                }
            }
            catch (Exception ex)
            {


            }
            return list;
        }
        /// <summary>
        ///  by 2020 ADD
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="query">查询条件</param>
        /// <param name="pageIndex">当前页</param>
        /// <param name="rows">行数</param>
        /// <param name="totalCount">总行数</param>
        /// <returns></returns>
        public List<T> FindPageNewAdd<T>(IMongoQuery query, int pageIndex, int rows, ref long totalCount)
        {
            List<T> list = new List<T>();
            int skipCount = 0;
            try
            {
                if (pageIndex > 1)
                {
                    skipCount = (pageIndex - 1) * rows;
                }
                else
                {
                    pageIndex = 1;
                }
                totalCount = this._db.GetCollection(typeof(T).Name).FindAs<T>(query).Count();
                if (totalCount > 0)
                {
                    list = this._db.GetCollection(typeof(T).Name).FindAs<T>(query).SetFlags(QueryFlags.NoCursorTimeout).SetSortOrder().SetSkip(skipCount).SetLimit(rows).ToList();
                }
            }
            catch (Exception)
            {


                throw;
            }
            return list;
        }




        /// <summary>
        /// 按条件分页查询
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="query">查询条件</param>
        /// <param name="pageIndex">页次</param>
        /// <param name="pageRow">每页显示记录数</param>
        /// <param name="total">总记录数</param>
        /// <returns></returns>
        public List<T> FindMoreForPageByCondion<T>(IMongoQuery query, int pageIndex, int pageRow, ref long total)
        {
            List<T> list = new List<T>();
            try
            {
                total = this._db.GetCollection(typeof(T).Name).FindAs<T>(query).Count();//获取总记录数
                if (pageIndex == 1)
                {
                    list = this._db.GetCollection(typeof(T).Name).FindAs<T>(query).SetSortOrder(SortBy.Descending("CreateDate")).SetLimit(pageRow).ToList();
                }
                else
                {
                    var bd = this._db.GetCollection(typeof(T).Name).Find(query).SetSortOrder("_id:1").SetLimit((pageIndex - 1) * pageRow).Last();   //获取最后一个ID主键
                    var el = bd.GetElement(0);
                    var value = el.Value;
                    list = this._db.GetCollection(typeof(T).Name).FindAs<T>(query).SetSortOrder("_id:1").SetSkip(pageRow).SetLimit(pageRow).ToList();
                }
            }
            catch (Exception ex)
            {


            }
            return list;
        }




        /// <summary>
        /// 更新实体单个字段值
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="whereField">条件字段</param>
        /// <param name="whereValue">条件字段值</param>
        /// <param name="updateField">修改字段</param>
        /// <param name="updateValue">修改字段值</param>
        /// <returns></returns>
        public bool UpdateEntity<T>(string whereField, string whereValue, string updateField, string updateValue)
        {
            bool isOk = true;
            try
            {
                var query = Query.EQ(whereField, whereValue);
                var update = Update.Set(updateField, updateValue);
                WriteConcernResult result = this._db.GetCollection(typeof(T).Name).Update(query, update);
                if (!result.Ok)
                    isOk = false;
            }
            catch (Exception ex)
            {


            }
            return isOk;
        }


        /// <summary>
        /// 更新整个实体模型字段
        /// </summary>
        /// <typeparam name="T">泛型参数</typeparam>
        /// <param name="whereField">条件字段</param>
        /// <param name="whereValue">条件值</param>
        /// <param name="updateEntity">实体模型</param>
        /// <returns>True:成功,False:失败</returns>
        public bool UpdateEntityMoreFields<T>(string whereField, string whereValue, T updateEntity)
        {
            bool isOk = true;
            try
            {


                var query = Query.EQ(whereField, whereValue);
                BsonDocument bsonDoc = updateEntity.ToBsonDocument(typeof(T));
                var update = new UpdateDocument{
                    {"$set",bsonDoc}
                };
                WriteConcernResult result = this._db.GetCollection(typeof(T).Name).Update(query, update);
                if (!result.Ok)
                    isOk = false;
            }
            catch (Exception ex)
            {


            }
            return isOk;
        }


        /// <summary>
        /// 删除实体文档
        /// </summary>
        /// <typeparam name="T">泛型参数</typeparam>
        /// <param name="whereField">条件字段</param>
        /// <param name="whereValue">条件值</param>
        /// <returns></returns>
        public bool DelEntity<T>(string whereField, string whereValue)
        {
            bool isOk = true;
            try
            {


                var query = Query.EQ(whereField, whereValue);
                WriteConcernResult result = this._db.GetCollection(typeof(T).Name).Remove(query);
                if (!result.Ok)
                    isOk = false;
            }
            catch (Exception ex)
            {


            }
            return isOk;


        }


        #endregion


        #region GridFS 文件操作
        /// <summary>
        ///
        /// </summary>
        /// <returns></returns>
        public MongoCursor<MongoGridFSFileInfo> FindAll()
        {
            return this._db.GetGridFS(MongoGridFSSettings.Defaults).FindAll();
        }


        /// <summary>
        ///
        /// </summary>
        /// <param name="filePath"></param>
        public void UploadFile(string filePath)
        {
            FileInfo fi = new FileInfo(filePath);
            this._db.GetGridFS(MongoGridFSSettings.Defaults).Upload(filePath, fi.Name);
        }
        /// <summary>
        ///
        /// </summary>
        /// <param name="filePath"></param>
        /// <param name="fileName"></param>


        public void UploadFile(string filePath, string fileName)
        {
            this._db.GetGridFS(MongoGridFSSettings.Defaults).Upload(filePath, fileName);
        }


        /// <summary>
        ///下载文件保存到默认目录
        /// </summary>
        /// <param name="fileName"></param>
        /// <param name="filePath"></param>
        public void DownloadFile(string fileName)
        {
            this._db.GetGridFS(MongoGridFSSettings.Defaults).Download(fileName);
        }
        /// <summary>
        ///下载文件保存到其他目录
        /// </summary>
        /// <param name="fileName"></param>
        /// <param name="filePath"></param>
        public void DownloadFileOther(string localFileName, string remoteFileName)
        {
            this._db.GetGridFS(MongoGridFSSettings.Defaults).Download(localFileName,remoteFileName);
        }
        /// <summary>
        ///
        /// </summary>
        /// <param name="fileName"></param>
        public void DeleteFile(string fileName)
        {
            this._db.GetGridFS(MongoGridFSSettings.Defaults).Delete(fileName);
        }
        /// <summary>
        ///
        /// </summary>
        public void DeleteAll()
        {
            foreach (var inst in this._db.GetGridFS(MongoGridFSSettings.Defaults).FindAll())
            {
                inst.Delete();
            }
        } 
        #endregion
    }
}

3、创建实体 User.cs

using MongoDB.Bson;
namespace MongoHelper.Model
{
    public class User
    {
        public ObjectId _id;
        public string name { get; set; }
        public int age { get; set; }
    }
}

4、调用示例代码

var list = new List<User>();
            for (int i = 0; i < 100; i++)
            {
                User user = new User();
                user.age = 20 + i;
                user.name = "测试" + i;
                list.Add(user);
            }
            //新增实体
            //tool.Add(list);
            //更新实体
            //tool.UpdateEntity<User>("name", "测试", "age", "99");
            //删除操作
            //tool.DelEntity<User>("name","测试");
            long total = 0;
            //构造查询条件
            IMongoQuery query = Query.And(
                Query.Matches("name", "1")
                );
            //分页查询数据
            var ll = tool.FindMoreForPageByCondion<User>(query, 0, 10, ref total);
            // 文件操作
            var model = tool.FindAllMore<User>();
            string folder = @"E:\photo";
            DirectoryInfo di = new DirectoryInfo(folder);
            //循环读取文件上传
            foreach (var file in di.GetFiles())
            {
                tool.UploadFile(file.FullName, file.Name);
            }
            var fileModel = tool.FindAll().First();
            // 保存文件指定目录
            tool.DownloadFileOther("D:\\"+fileModel.Name, fileModel.Name);//下载文件到当前目录
            pictureBox1.ImageLocation = "D:\\"+fileModel.Name;

具体的代码地址：https://gitee.com/hgm1989/mongodb-demo

如有问题可以随时沟通交流。

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