using (ShopDbContext shopDbContext = new ShopDbContext())
            {
                var orderEntry = new OrderEntryModel();
                orderEntry.OrderRefId = cart.Id;
                orderEntry.Product = shopDbContext.Products.First(product => product.Code.Equals(productCode));
                orderEntry.Quantity = quantity;

                shopDbContext.OrderEntries.Add(orderEntry);
                shopDbContext.SaveChanges();
            }