public ActionResult _AddInvoiceItem(Guid providerId, AddInvoiceItem addInvoiceItem)
        {
            if (this.ModelState.IsValid)
            {
                addInvoiceItem.ExecuteNonQuery();
                return(Redirect($"/Providers/Invoices/Invoice/View/{addInvoiceItem.InvoiceId}"));
            }

            return(View("FormPage", addInvoiceItem));
        }
        public ActionResult _AddInvoiceItem(AddInvoiceItem addInvoiceItem)
        {
            if (this.ModelState.IsValid)
            {
                addInvoiceItem.ExecuteNonQuery();
                return(Redirect(string.Format("/Invoice/{0}", addInvoiceItem.Id)));
            }

            return(View("FormPage", addInvoiceItem));
        }