/// <summary>
        /// Delete all local buffer data from database
        /// and query again
        /// </summary>
        /// <returns></returns>
        private async Task DeleteAll()
        {
            CurrentDialogType = DatabaseViewDialogType.WaitingDialog;
            await FaiCollectionHelper.DeleteByDateTimeAsync(DatabaseBuffer.FaiCollectionBuffers,
                                                            NameConstants.SqlConnectionString);

            await QueryByIntervalAsync();

            ShouldDisplayDialog = false;
        }
        private async Task DeleteSelection()
        {
            CurrentDialogType = DatabaseViewDialogType.WaitingDialog;

            // Delete in database
            await FaiCollectionHelper.DeleteByDateTimeAsync(SelectedCollections, NameConstants.SqlConnectionString);

            // Get last index in buffer before selections
            var indexOfFirstSelectedCollections = DatabaseBuffer.FaiCollectionBuffers.IndexOf(SelectedCollections[0]);
            var lastIndexBeforeSelections       =
                indexOfFirstSelectedCollections == 0 ? 0 : indexOfFirstSelectedCollections - 1;
            // Calculate the page index of lastIndexBeforeSelection
            var pageIndex = (int)Math.Floor(lastIndexBeforeSelections / (double)DatabaseBuffer.RowsPerPage);

            // Remove selections from buffer
            DatabaseBuffer.Remove(SelectedCollections);
            // Navigate to page where the first selection is deleted
            DatabaseBuffer.NavigateToPage(pageIndex);

            ShouldDisplayDialog = false;
        }