错误的List

BookContext db=new BookContext();

public ActionResult Index(int XX)
{
List<BookType> booktypes = new List<BookType>()
{
new BookType{id=1,Booktype="aaa"},
new BookType{id=2,Booktype="zzz"},
new BookType{id=3,Booktype="ccc"},
};
ViewBag.booktypes = booktypes;
var XXX = db.books.Select(XX =>XXX.Amount).Min();
return View(booktypes);