Mongodb 批量Upsert

        List<UpdateOneModel<Entity>> requests = new List<UpdateOneModel<Entity>>(entities.Count());

        foreach (var entity in entities)

        {

            var filter = new FilterDefinitionBuilder<Entity>().Where(m => m.Field1 == entity.Field1 && m.Field2== entity.Field2);

            var update = new UpdateDefinitionBuilder<Entity>().Set(m => m.Field1, entity.Field1).Set(m => m.Field2, entity.Field2);

            var request = new UpdateOneModel<Entity>(filter, update);

            request.IsUpsert = true;

            requests.Add(request);

        }

        await Collection.BulkWriteAsync(requests);

var advisorEmails = Database.GetCollection<AdvisorEmail>(Settings.AdvisorEmailCollection).Find(Builders<AdvisorEmail>.Filter.In(x => x.Id, dicAdvisorEmail.Keys)).ToList();

					if (advisorEmails != null && advisorEmails.Count > 0) {

						List<UpdateOneModel<AdvisorEmail>> lstUpdateActions = new List<UpdateOneModel<AdvisorEmail>>();

						List<string> lstRemoveAdvisorEmailIds = new List<string>();

						foreach (AdvisorEmail advisorEmail in advisorEmails)

						{

							if (dicAdvisorEmail.ContainsKey(advisorEmail.Id)) {

								List<string> lstRemoveIds = dicAdvisorEmail[advisorEmail.Id];

								List<string> lstnewIds = new List<string>();

								foreach (string s in advisorEmail.ClientIds) {

									if (!lstRemoveIds.Contains(s)) lstnewIds.Add(s);

								}

								if (lstnewIds.Count > 0)

								{

									var filter = new FilterDefinitionBuilder<AdvisorEmail>().Where(m => m.Id == advisorEmail.Id);

									var update = new UpdateDefinitionBuilder<AdvisorEmail>().Set(m => m.ClientIds, lstnewIds);

									var action = new UpdateOneModel<AdvisorEmail>(filter, update);

									action.IsUpsert = true;

									lstUpdateActions.Add(action);

								}

								else {

									lstRemoveAdvisorEmailIds.Add(advisorEmail.Id);

								}

							}

						}

						if (lstUpdateActions.Count > 0)

							Database.GetCollection<AdvisorEmail>(Settings.AdvisorEmailCollection).BulkWrite(lstUpdateActions);

						if (lstRemoveAdvisorEmailIds.Count > 0)

							LocalAdvisorEmailDB.DeleteMany(Filter<AdvisorEmail>().In(x => x.Id, lstRemoveAdvisorEmailIds));

					}