public class BaseEntity

    {

        /// <summary>

        /// 字段映射，告诉mongodb这个字段在数据库中对应_id

        /// </summary>

        [BsonId]

        //告诉mongodb这个字段在数据库中的类型是ObjectId

        [BsonRepresentation(BsonType.ObjectId)]

        public string _id { get; set; }

    }

   public class IPInfo : BaseEntity

    {

        public string ip { get; set; }

        public string ipAddress { get; set; }

        public string addTime { get; set; }

    }

   public class IPDetails : BaseEntity

    {

        /// <summary>

        /// 主表id

        /// </summary>

        [BsonRepresentation(BsonType.ObjectId)]

        public string parentId { get; set; }

        public string ipAddress { get; set; }

        public string ipNetwork { get; set; }

        public string ipBrowser { get; set; }

        public string addTime { get; set; }

    }

自定义实体类

public class IPInfoFactory

    {

        /// <summary>

        /// 集合（表）名称

        /// </summary>

        private static readonly string CollectionName = "IPInfo";

        //ip子表名称

        private static readonly string ChildCollectionName = "IPDetail";

        private static IMongoDatabase db = MongoDb.GetMongoDb();

        public static List<IPInfo> GetAllList()

        {

            try

            {

                var collection = db.GetCollection<IPInfo>(CollectionName);

                List<IPInfo> list = collection.Find(new BsonDocument()).ToList();

                return list;

            }

            catch (Exception ex)

            {

                return null;

            }

        }

        /// <summary>

        /// 插入主表

        /// </summary>

        /// <returns></returns>

        public static bool Add(string ip, string ipAddress)

        {

            try

            {

                var IPInfoCollection = db.GetCollection<IPInfo>(CollectionName);

                IPInfo ipInfo = new IPInfo();

                ipInfo.ip = ip;

                ipInfo.ipAddress = ipAddress;

                ipInfo.addTime = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss:fff");

                IPInfoCollection.InsertOne(ipInfo);

                return true;

            }

            catch (Exception ex)

            {

                return false;

            }

        }

        /// <summary>

        /// 插入主表、子表：

        /// 主表：有则不插入，无则插入;

        /// 子表：一条数据都没有，则插入，已经存在数据，判断是否存在一条相同数据，存在则不插入，不存在则插入。

        /// </summary>

        /// <param name="ip">ip</param>

        /// <param name="model">ip接口获取的信息</param>

        /// <param name="ipBrowser">浏览器</param>

        /// <returns></returns>

        public static bool AddIPInfoAndDetail(string ip, ApiIPInfo model, string ipBrowser = "")

        {

            try

            {

                //ip地址

                var ipAddress = model.Address;

                //ip网络

                var ipNetwork = model.Network;

                var IPInfoCollection = db.GetCollection<IPInfo>(CollectionName);

                var IPDetailCollection = db.GetCollection<IPDetails>(ChildCollectionName);

                //判断主表是否已经存在

                var pFilter = Builders<IPInfo>.Filter.Eq("ip", ip);

                var parentItem = IPInfoCollection.Find(pFilter).FirstOrDefault();

                if (parentItem == null)

                {

                    //插入主表

                    IPInfo ipInfo = new IPInfo();

                    ipInfo.ip = ip;

                    ipInfo.ipAddress = ipAddress;

                    ipInfo.addTime = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss:fff");

                    IPInfoCollection.InsertOne(ipInfo);

                    //插入子表

                    string parent_id = string.Empty;

                    //刚插入的主表

                    var parentItemNew = IPInfoCollection.Find(pFilter).FirstOrDefault();

                    if (parentItemNew != null)

                    {

                        parent_id = parentItemNew._id;

                        AddChild(parent_id, ipAddress, ipNetwork, ipBrowser);

                    }

                }

                else

                {

                    string parent_id = parentItem._id;

                    var childFilter1 = Builders<IPDetails>.Filter.Eq("parentId", parent_id);

                    var childItem = IPDetailCollection.Find(childFilter1).FirstOrDefault();

                    if (childItem == null)

                    {

                        AddChild(parent_id, ipAddress, ipNetwork, ipBrowser);

                    }

                    else

                    {

                        //如果没有类似的数据，则插入

                        var filterBuilder = Builders<IPDetails>.Filter;

                        var childFilter2 = filterBuilder.Eq("parentId", parent_id)

                            & filterBuilder.Regex("ipNetwork", new BsonRegularExpression(new Regex(ipNetwork)))

                            & filterBuilder.Regex("ipBrowser", new BsonRegularExpression(new Regex(ipBrowser)));

                        var childItem2 = IPDetailCollection.Find(childFilter2).FirstOrDefault();

                        if (childItem2 == null)

                        {

                            AddChild(parent_id, ipAddress, ipNetwork, ipBrowser);

                        }

                    }

                }

                return true;

            }

            catch (Exception ex)

            {

                return false;

            }

        }

        /// <summary>

        /// 插入子表

        /// </summary>

        /// <returns></returns>

        public static bool AddChild(string parentId, string ipAddress, string ipNetwork, string ipBrowser)

        {

            try

            {

                var IPDetailCollection = db.GetCollection<IPDetails>(ChildCollectionName);

                IPDetails ipDetails = new IPDetails();

                ipDetails.parentId = parentId;

                ipDetails.addTime = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss:fff");

                ipDetails.ipAddress = ipAddress;

                ipDetails.ipNetwork = ipNetwork;

                ipDetails.ipBrowser = ipBrowser;

                IPDetailCollection.InsertOne(ipDetails);

                return true;

            }

            catch (Exception ex)

            {

                return false;

            }

        }

        /// <summary>

        /// 插入子表

        /// </summary>

        /// <returns></returns>

        public static bool AddChild(IPDetails model)

        {

            try

            {

                var IPDetailCollection = db.GetCollection<IPDetails>(ChildCollectionName);

                IPDetails ipDetails = new IPDetails();

                ipDetails.parentId = model.parentId;

                ipDetails.addTime = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss:fff");

                ipDetails.ipAddress = model.ipAddress;

                ipDetails.ipNetwork = model.ipNetwork;

                ipDetails.ipBrowser = model.ipBrowser;

                IPDetailCollection.InsertOne(ipDetails);

                return true;

            }

            catch (Exception ex)

            {

                return false;

            }

        }

    }