public void Insert(Author author)
        {
            db.Authors.Add(author);

            db.SaveChanges();
        }
        public void Update(Author author)
        {
            db.Entry(author).State = EntityState.Modified;

            db.SaveChanges();
        }
        public void Delete(Author author)
        {
            db.Authors.Remove(author);

            db.SaveChanges();
        }