public IEnumerable <Historial> Get()
 {
     using (HistorialDBEntities db = new HistorialDBEntities())
     {
         return(db.Historial.ToList());
     }
 }
        public void Insert(string record)
        {
            Historial _historial = new Historial();

            _historial.Valor = record;
            using (HistorialDBEntities db = new HistorialDBEntities())
            {
                db.Historial.Add(_historial);
                db.SaveChanges();
            }
        }