public void AddProduct(Product product) { Product prodFromList = ProductMethods.GetProductById(product, ConnectionString); if (prodFromList == null) { if (product.Name.Length <= 200) { ProductMethods.AddProduct(product, ConnectionString); } } else { ProductMethods.UpdateProduct(ConnectionString, $"update PRODUCTS set ProductCount += {product.Count} where Id = {prodFromList.Id};"); } }