public void AddNew(UserModel userModel, ProductModel productModel) { using (var context = _unitOfWorkFactory.Create()) { var user = _userRepository.GetById(userModel.Id); var product = _productRepository.GetById(productModel.Id); var transaction = new TransactionModel() { Product = product, User = user }; _transactionRepository.AddNew(transaction.ToStoredItem()); context.SaveChanges(); } }