public static void WrtieAllBook(int index = 1)
 {
     for (int i = 0; i < COUNT; i++)
     {
         Book b = GetBook(i);
         using (BookDao dao = new BookDao())
             dao.add(b);
     }
 }
 public static void WrtieBook(int index)
 {
     Book b = GetBook(index);
     using (BookDao dao = new BookDao())
         dao.add(b);
 }