如何在实体框架中给出列长

Question

 public IActionResult DeleteSystemCode(SystemCode model, int Id,int Length)
        {
            //ViewBag.getValue = TempData["Message"];

        //var model = new SystemCode();
        //using (var db = _iServiceProvider.GetRequiredService<ApplicationDbContext>())
        //{
        model = _context.systemCode.Len(code).Where(b => b.ID == Id).SingleOrDefault();
        if (model == null)
        {
            //ViewBag.getValue = TempData["Message"];
            //string code = model.code;
            return RedirectToAction("Index");
        }
}