public ActionResult Edit(PriceListAndColumnsViewModel priceListAndColumns)
        {
            if (ModelState.IsValid)
            {
                var priceList = priceListAndColumns.PriceList;
                _db.MarkAsModified(priceList);
                var columns = priceListAndColumns.Columns;
                foreach (var column in columns)
                {
                    _db.MarkAsModified(column);
                }
                _db.SaveChanges();
                return(RedirectToAction("Index"));
            }

            priceListAndColumns.Columns = _db.Columns.Where(c => c.PriceListId == priceListAndColumns.PriceList.Id).ToList();
            return(View(priceListAndColumns));
        }
        // GET: PriceLists/Edit/5
        public ActionResult Edit(int?id)
        {
            if (id == null)
            {
                return(new HttpStatusCodeResult(HttpStatusCode.BadRequest));
            }
            var priceList = _db.PriceLists.Find(id);

            if (priceList == null)
            {
                return(HttpNotFound());
            }

            var columns             = _db.Columns.Where(c => c.PriceListId == priceList.Id).ToList();
            var priceListAndColumns = new PriceListAndColumnsViewModel(priceList)
            {
                Columns = columns
            };

            return(View(priceListAndColumns));
        }