public IActionResult Add(UserBooksModel model)
        {
            var userId = _httpContextAccessor.HttpContext.Session.GetString("UserId");

            var query = from user in _context.User
                        where user.Id.ToString() == userId
                        select user;
            var currentUser = query.FirstOrDefault();

            if (ModelState.IsValid)
            {
                //currentUser.Books.Add(model);
                //_context.User.Update(currentUser);
                //_context.SaveChanges();

                model.User   = currentUser;
                model.UserId = currentUser.Id;
                _context.Books.Add(model);
                _context.SaveChanges();

                var redirectUrl = Url.Action("Index", "Books", HttpContext.Request.Scheme);
                return(Redirect(redirectUrl));
            }
            return(View(model));
        }
        public IHttpActionResult GetBorrowBooks(int id)
        {
            var userBooks = (from brb in db.BorrowBooks
                             join std in db.Students on brb.StudentID equals std.studentID
                             where std.studentID == id
                             select new
            {
                brb.BookID,
                brb.BookTitle,
                brb.BorrowDate,
                brb.MyBorrowID,
                brb.StudentID
            });


            var nonUserBooks = (from brb in db.BorrowBooks
                                join std in db.Students on brb.StudentID equals std.studentID
                                where std.studentID != id
                                select new
            {
                brb.MyBorrowID,
                brb.BookID,
                brb.BookTitle,
            });

            UserBooksModel mdl_UserBooks = new UserBooksModel();

            mdl_UserBooks.userBooks    = userBooks;
            mdl_UserBooks.nonUserBooks = nonUserBooks;

            return(Json(mdl_UserBooks));
        }