SmartDeviceProject1.SqlCeStorageHandler.ResetDirtyAndDeleteTombstones C# (CSharp) Method

        public void ResetDirtyAndDeleteTombstones()
        {
            using (GetSqlCeConnection())
            {
                SqlCeTransaction transaction = _connection.BeginTransaction();

                try
                {
                    using (var command = new SqlCeCommand())
                    {
                        command.CommandText =
                            "DELETE FROM [TagItemMapping] WHERE [IsTombstone]=1;";
                        command.Connection = GetSqlCeConnection();

                        command.ExecuteNonQuery();
                    }

                    using (var command = new SqlCeCommand())
                    {
                        command.CommandText =
                            "UPDATE [TagItemMapping] SET [IsDirty]=0 WHERE [IsDirty]=1";
                        command.Connection = GetSqlCeConnection();

                        command.ExecuteNonQuery();
                    }

                    using (var command = new SqlCeCommand())
                    {
                        command.CommandText =
                            "DELETE FROM [Item] WHERE [IsTombstone]=1;";
                        command.Connection = GetSqlCeConnection();

                        command.ExecuteNonQuery();
                    }

                    using (var command = new SqlCeCommand())
                    {
                        command.CommandText =
                            "UPDATE [Item] SET [IsDirty]=0 WHERE [IsDirty]=1";
                        command.Connection = GetSqlCeConnection();

                        command.ExecuteNonQuery();
                    }

                    using (var command = new SqlCeCommand())
                    {
                        command.CommandText =
                            "DELETE FROM [List] WHERE [IsTombstone]=1;";
                        command.Connection = GetSqlCeConnection();

                        command.ExecuteNonQuery();
                    }

                    using (var command = new SqlCeCommand())
                    {
                        command.CommandText =
                            "UPDATE [List] SET [IsDirty]=0 WHERE [IsDirty]=1";
                        command.Connection = GetSqlCeConnection();

                        command.ExecuteNonQuery();
                    }

                    transaction.Commit();
                }
                catch
                {
                    transaction.Rollback();
                    throw;
                }
            }
        }

        /// <summary>
        /// OfflineSyncProvider method implementation called when a change set returned from GetChangeSet has been
        /// successfully uploaded.
        /// </summary>
        /// <param name="state">The unique identifier passed in to the GetChangeSet call.</param>
        /// <param name="response">ChangeSetResponse that contains an updated server blob and any conflicts or errors that
        /// happened on the service.</param>
        public override void OnChangeSetUploaded(Guid state, ChangeSetResponse response)
        {
            if (null == response)
            {
                throw new ArgumentNullException("response");
            }

            if (null != response.Error)
            {
                throw new Exception("Exception during sync!");
            }

            var storageHandler = new SqlCeStorageHandler();
            if (null != response.UpdatedItems && 0 != response.UpdatedItems.Count)
            {
                foreach (var item in response.UpdatedItems)
                {
                    var offlineEntity = (SqlCeOfflineEntity) item;
                    storageHandler.ApplyItem(offlineEntity);
                }
            }

            if (null != response.Conflicts && 0 != response.Conflicts.Count)
            {
                foreach (var conflict in response.Conflicts)
                {
                    // We have an conflict so apply the LiveEntity
                    var liveEntity = (SqlCeOfflineEntity)conflict.LiveEntity;

                    // For a SyncError, which resulted from a client insert, the winning item may be a tombstone version
                    // of the client entity. In this case, the ServiceMetadata.Id property of the LiveEntity will be null.
                    // We need to lookup the item using primary keys in order to update it.
                    if (conflict.GetType() == typeof(SyncError))
                    {
                        var errorEntity = ((SyncError) conflict).ErrorEntity;

                        if (!liveEntity.ServiceMetadata.IsTombstone)
                        {
                            // If the live entity is not a tombstone, then we just need to update the entity.
                            storageHandler.ApplyItem(liveEntity);
                        }
                        else
                        {
                            // At this point, the LiveEntity is a tombstone and does not have primary key info.

                            // If the live entity is a tombstone, then delete the item by looking up the primary key
                            // from the error entity.
                            // The error entity in this case will have both Id and the primary keys.
                            errorEntity.ServiceMetadata.IsTombstone = true;
                            errorEntity.ServiceMetadata.Id = null;
                            storageHandler.ApplyItem((SqlCeOfflineEntity) errorEntity);
                        }
                    }
                    else
                    {
                        storageHandler.ApplyItem(liveEntity);
                    }
                }
            }

            // Clear all the isdirty flags and delete all rows with IsTombstone = true
            storageHandler.ResetDirtyAndDeleteTombstones();

            storageHandler.SaveAnchor(response.ServerBlob);
        }