public static void AddBook(string authorName,
string title, string webSite, string ISBN, string price)
{
BookStoreEntities context = new BookStoreEntities();
Book newBook = new Book();
newBook.Authors.Add(CreateOrLoadUser(context, authorName));
newBook.Title = title;
newBook.WebSite = webSite;
newBook.ISBN = ISBN;
if (authorName == null || title == null)
{
throw new ArgumentNullException("AuthorName and BookTitle has not to be null");
}
context.Books.Add(newBook);
context.SaveChanges();
}
private static Author CreateOrLoadUser(
BookStoreEntities context, string authorName)
{
Author existingAuthor = context.Authors.FirstOrDefault(x => x.Name == authorName);
if (existingAuthor != null)
{
return existingAuthor;
}
Author newAuthor = new Author();
newAuthor.Name = authorName;
context.Authors.Add(newAuthor);
context.SaveChanges();
return newAuthor;
}