public void RemoveRating(string name)
 {
     using (var db = new SudokuContext())
     {
         db.Remove(db.Ratings.Single(c => c.Name == name));
         db.SaveChanges();
     }
 }
        public void RemoveComment(string name)
        {
            //var sql="DELETE FROM Comment WHERE Name= {}"

            using (var db = new SudokuContext())
            {
                db.Remove(db.Comments.First(c => c.Name == name));
                db.SaveChanges();
            }
        }