public string AddBook(string isbn)
{
Book book = _bookDetailsRetrievalService.RetrieveBookInfo(isbn);
if (book != null)
{
book = _dao.Create(book);
return(book.ISBN);
}
else
{
throw new EntityDoesNotExistException($"ISBN {isbn} cannot be found");
}
}
public string Create(Book book)
{
var number = _bookDao.Create(book);
return(number > 0 ? $"Добавление успешно" : $"Ошибка при добавлении книги");
}