public IActionResult upDate(int id, StudentEditModelAdd model)
 {
     if (ModelState.IsValid)
     {
         var student = _repositoryStudent.GetStudentById(id);
         if (student == null)
         {
             return(RedirectToAction(nameof(Index)));
         }
         student.Name = model.Name;
         _repositoryStudent.upDate(student);
         return(RedirectToAction(nameof(Details), new { student.id }));
     }
     else
     {
         return(RedirectToAction(nameof(Index)));
     }
 }