//Get-Update
        public IActionResult Update(int?id)
        {
            AstronautVM AstronautVM = new AstronautVM()
            {
                Astronaut    = new Astronaut(),
                RoleDropDown = _db.Roles.Select(i => new SelectListItem
                {
                    Text  = i.Name,
                    Value = i.Id.ToString()
                })
            };

            if (id == null || id == 0)
            {
                return(NotFound());
            }

            AstronautVM.Astronaut = _db.Astronauts.Find(id);


            if (AstronautVM.Astronaut == null)
            {
                return(NotFound());
            }

            return(View(AstronautVM));
        }
        public IActionResult Create(AstronautVM obj)
        {
            if (ModelState.IsValid)
            {
                _db.Astronauts.Add(obj.Astronaut);
                _db.SaveChanges();
                return(RedirectToAction("Index"));
            }

            return(View(obj));
        }
        //GET-Create
        public IActionResult Create()
        {
            AstronautVM astronautVM = new AstronautVM()
            {
                Astronaut    = new Astronaut(),
                RoleDropDown = _db.Roles.Select(i => new SelectListItem
                {
                    Text  = i.Name,
                    Value = i.Id.ToString()
                }).ToList()
            };

            return(View(astronautVM));
        }