摘要

在实际开发中遇到更新某个document中的数组的值，这里做一下记录。

这里使用的驱动为

using MongoDB.Bson;

using MongoDB.Driver;

相关文章

demo

using MongoDB.Bson;using MongoDB.Driver;using MongoDB.Driver.Builders;using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace Wolfy.Mongodb{    class Program    {        static void Main(string[] args)        {        }    }    class MongoHelper    {        private static readonly string _db = "";        private static readonly string _col = "";        private static readonly string _ip = "";        private static readonly string _user = "";        private static readonly string _pwd = "";        private static readonly string _connStr = string.Format("mongodb://{0}:{1}@{2}:27017/{3}", _user, _pwd, _ip, _db);        /// 
        /// 为某个userId添加friend，如果数组中不存在则添加        /// 
        ///         ///         /// 
             public static bool UpdateOrInsert(string userId, string friendId)        {            var col = GetCollection();            var query = new QueryDocument { { "userId", userId }, new QueryDocument { { "$nin", new BsonArray().Add(friendId) } } };            var update = Update.Push("friends", friendId).Inc("count", 1);            return col.Update(query, update, UpdateFlags.None).Ok;        }        private static MongoCollection
     
       GetCollection()        {            MongoClient client = new MongoClient(_connStr);            MongoServer server = client.GetServer();            var db = server.GetDatabase(_db);            var col = db.GetCollection(_col);            return col;        }        /// 
      
        /// 从属性中移除好友        /// 
        /// 
              /// 
              /// 
              public static bool RemoveFriend(string userId, string friendId)        {            var col = GetCollection();            var query = new QueryDocument { { "userId", userId } };            MongoDB.Driver.Builders.UpdateBuilder builder = new MongoDB.Driver.Builders.UpdateBuilder();            builder.Pull("friends", friendId);            return col.Update(query, builder, UpdateFlags.None).Ok;        }        /// 
      
        /// 更新字段值        /// 
        /// 
              /// 
              /// 
              public static bool UpdateFields(string userId, Dictionary
      
        dic)        {            var col = GetCollection();            var query = new QueryDocument { { "userId", userId } };            MongoDB.Driver.Builders.UpdateBuilder builder = new MongoDB.Driver.Builders.UpdateBuilder();            foreach (var item in dic.Keys)            {                builder.Set(item, BsonValue.Create(dic[item]));            }            builder.Set("dt", DateTime.Now);            return col.Update(query, builder, UpdateFlags.Upsert).Ok;        }    }}
      
     

代码

上述是好友列表中的操作。如果好友列表中已经存在，则不再添加，否则添加。省略用c#在做业务的判断了。其实有很多，都可以交给mongodb去做，可以在代码中少很多的if-else。