static void Main(string[] args) { var userDataAccess = new UserDataAccess(); var bookDataAccess = new BookDataAccess(); var authorDataAccess = new AuthorDataAccess(); var debtorUsers = userDataAccess.SelectDebtorUsers(); var books = bookDataAccess.SelectAll(); var authors = authorDataAccess.SelectAll(); var bookNumberThree = bookDataAccess.SelectById(3); var userNumberTwo = userDataAccess.SelectById(2); foreach (var user in debtorUsers) { Console.WriteLine(user.ToString()); } foreach (var authorId in bookNumberThree.Authors) { foreach (var author in authors) { if (authorId == author.Id) { Console.WriteLine(author.ToString()); break; } } } foreach (var book in books) { if (book.Status) { Console.WriteLine(book.ToString()); } } foreach (var bookId in userNumberTwo.Books) { foreach (var book in books) { if (bookId == book.Id) { Console.WriteLine(book.ToString()); break; } } } userDataAccess.UpdateDebtorUsers(); }