public async Task <IActionResult> EditSingleInvoiceItems([FromBody] IEnumerable <Item> items) { var itemsList = items.ToList(); var distinctCount = itemsList.Select(i => i.InvoiceId).Distinct().Count(); if (distinctCount != 1) { return(BadRequest("Items of multiple invoices received.")); } var notExistingItems = await _invoicesRepository.GetNotExistingItems(itemsList); if (notExistingItems.Any()) { return(NotFound(notExistingItems)); } await _invoicesRepository.UpdateItemsOfSingleInvoiceAsync(itemsList); return(Ok()); }