EF 分组查询

var result = from m in userPrefers.GroupBy(t => new { t.Pet_Preferential.Merchant.MerchantId, t.Pet_Preferential.Merchant.MerchantName })
                         select new
                         {
                             MerchantId = m.Key.MerchantId,
                             MerchantName = m.Key.MerchantName,
                             Preferential = from u in m
                                            orderby u.Pet_Preferential.MinAmount descending
                                            select new
                                            {
                                                Id = u.Id,
                                                PreferentialId = u.Pet_Preferential.Id,
                                                Context = u.Pet_Preferential.Context,
                                                isDiscount = u.Pet_Preferential.isDiscount,
                                                MinAmount = u.Pet_Preferential.MinAmount,
                                                Preferential = u.Pet_Preferential.Preferential,
                                                UseCondition = u.Pet_Preferential.UseCondition,
                                                ProSales = u.Pet_Preferential.ProSales,
                                                PreferentialNum = u.Pet_Preferential.PreferentialNum,
                                            }
                         };