C# 操作 MongoDB

今项目使用Mongodb，C#操作MongoDB使用MongoDB.Driver.dll库(Nuget)，写了个小Demo，如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Text;
using MongoDB.Driver;

namespace MongoBase
{
    internal class MongoBase
    {
        private static string _connStr = "mongodb://root:123456@127.0.0.1:27017";
        private static string _dbName = "test";

        private static MongoUrl url = new MongoUrl(_connStr);
        private static MongoClient client = new MongoClient(url);
        public static IMongoDatabase db = client.GetDatabase(_dbName);
    }

    public class MongoHelper<TEntity>
    {
        public string Name => typeof(TEntity).Name;
        public IMongoCollection<TEntity> Collection => MongoBase.db.GetCollection<TEntity>(Name);
        public List<TEntity> Queryable => Collection.AsQueryable().ToList();

        public FilterDefinitionBuilder<TEntity> Filter => Builders<TEntity>.Filter;

        public UpdateDefinitionBuilder<TEntity> Update => Builders<TEntity>.Update;

        public ProjectionDefinitionBuilder<TEntity>Projection=> Builders<TEntity>.Projection;
    }

}

using System;
using System.Collections.Generic;
using System.Text;
using MongoDB.Bson;
using MongoDB.Bson.Serialization.Attributes;

namespace MongoBase
{
    public class EntityBase
    {
        public EntityBase()
        {
            _id = ObjectId.GenerateNewId();
            createTime = DateTime.Now;
            isDelete = false;
            id = _id.ToString();
        }
        [BsonId]
        public ObjectId _id { get; set; }
        public string id { get; set; }

        public DateTime? createTime { get; set; }

        public bool? isDelete { get; set; }

    }

}

using MongoBase;
using MongoDB.Bson;
using MongoDB.Bson.Serialization.Attributes;

namespace ConsoleApp5
{
    internal class Video : EntityBase
    {
        public string Title { get; set; }

        public string Category { get; set; }

        public int Minutes { get; set; }

        public string Comments { get; set; }
    }
}

using System;
using System.Collections.Generic;
using MongoBase;
using MongoDB.Bson;
using MongoDB.Driver;
using MongoDB.Driver.Linq;

namespace ConsoleApp5
{
    class Program
    {
        static void Main(string[] args)
        {
            MongoHelper<Video> videoHelper = new MongoHelper<Video>();

            //新增
            videoHelper.Collection.InsertOne(new Video()
            {
                Title = "ggg"
            });
            //查找集合
            var list = videoHelper.Collection.Find(videoHelper.Filter.Eq(e => e.Category, "Horror")).ToList();

            list = videoHelper.Collection.Find(videoHelper.Filter.Eq(e => e.Title, "ggg")).ToList();

            //方式一：拼接查找条件
            List<FilterDefinition<Video>> listFilter = new List<FilterDefinition<Video>>()
            {
                videoHelper.Filter.Eq(e=>e.Minutes,),
                videoHelper.Filter.Eq(e=>e.Title,"The Perfect Developer")
            };

            //根据查找多个条件筛选集合
            list = videoHelper.Collection.Find(videoHelper.Filter.And(listFilter)).ToList();

            //方式二：拼接查找条件
            var filter = videoHelper.Filter.Eq(e => e.Title, "cys") & videoHelper.Filter.Eq(e => e.Category, "cys");

            list = videoHelper.Collection.Find(filter).ToList();

            //拼接更新字段
            var updateDefinition = new List<UpdateDefinition<Video>>()
            {
                videoHelper.Update.Set(e=>e.Title, "cys"),
                videoHelper.Update.Set(e=>e.Category, "cys")
            };

            //按照条件更新
            videoHelper.Collection.UpdateMany(videoHelper.Filter.And(listFilter),
                videoHelper.Update.Combine(updateDefinition));

            //删除
            videoHelper.Collection.DeleteOne(videoHelper.Filter.Eq(e => e.Title, "Lost In Frankfurt am Main"));

            //获取某个字段
            filter = videoHelper.Filter.Eq(e => e.Title, "ggg");
            var bson = videoHelper.Collection.Find(filter).Project(videoHelper.Projection.Include(e => e.Title).Exclude(e => e._id)).FirstOrDefault();
        }
    }
}

注：时间类型的属性，存入MongoDB后会比北京时间少8小时，是由于默认写入的是世界标准时间，可在时间类型属性上添加

[BsonDateTimeOptions(Kind = DateTimeKind.Local)]
public DateTime createTime { get; set; }

的特性，这样取出来之后就是北京时间。