group by HAVING count()>10 用linq 写

            var queryGBN =
                 from q in dt.AsEnumerable()
                 group q by new { Doc_Type = q.Field<string>("Doc_Type"), Packing_Method = q.Field<string>("Packing_Method"), Packing_Method_Desc = q.Field<string>("Packing_Method_Desc") }
                  into g where g.Count()>1   select new {  g.Key        };