public string GetUserPrizeChangeListRamdom(string customerId, int userid)

        {

            if (!customerId.Equals(""))

                using (var db = new SqlServer())

                {

                    var updateSql = string.Format(@"DECLARE @parimaryTable  Table(prizecode varchar(50));

update top (1)  UserPrizeChangeList set consumerid='{0}' ,userid={1},status=1,usetime=getdate() output deleted.prizecode into @parimaryTable where status=0  ; select * from @parimaryTable", db.InjectReplace(customerId), userid);

                    return db.GetScalar<string>(updateSql);

                }

            else

                return null;

        }