C# ling to sql 取多条记录最大时间

     var _setlist = (from f in _postgredbcontext.settlements
                              
                                 group f by ( new { f.settlement_code })into g
                                 select new
                                 {
                                     deal_time = g.max(m => m.deal_time),
                                     g.key.settlement_code

                                 }).asnotracking().tolist();