private static void AddDefault(int invoiceId, int subcategoryType, int?assCounterId)
        {
            InvoiceSubcategories result = new InvoiceSubcategories
            {
                Id_Invoice      = invoiceId,
                Id_subCategType = subcategoryType,
                id_assCounter   = assCounterId
            };

            GetContext().InvoiceSubcategories.Add(result);
            GetContext().SaveChanges();
        }
        public static void Update(InvoiceSubcategories invoiceSubcategory)
        {
            InvoiceSubcategories result;

            result = GetByInvoiceId(invoiceSubcategory.Id_Invoice, invoiceSubcategory.Id_subCategType, invoiceSubcategory.id_assCounter);

            if (result != null && (result.Value != invoiceSubcategory.Value || result.quantity != invoiceSubcategory.quantity ||
                                   result.PricePerUnit != invoiceSubcategory.PricePerUnit || result.VAT != invoiceSubcategory.VAT ||
                                   result.service != invoiceSubcategory.service || result.penalties != invoiceSubcategory.penalties))
            {
                result.quantity      = invoiceSubcategory.quantity;
                result.PricePerUnit  = invoiceSubcategory.PricePerUnit;
                result.VAT           = invoiceSubcategory.VAT;
                result.service       = invoiceSubcategory.service;
                result.penalties     = invoiceSubcategory.penalties;
                result.Value         = invoiceSubcategory.Value;
                result.id_assCounter = invoiceSubcategory.id_assCounter;

                GetContext().Entry(result).CurrentValues.SetValues(result);
                GetContext().SaveChanges();
            }
        }