var _date = DateTime.Now.Date;var q = from p in AdDividend.ObjectSet()        where EntityFunctions.TruncateTime(p.SettlementDate) == _date        group p by p.UserId into g        select new                  {                    g.Key,                    DayMaxGold = g.Sum(p => p.GoldNum)                  };if (q != null){   _DayMaxGold = q.Max(c => c.DayMaxGold);}