Can You Show Me A Better Way?

I need to flag old records and new records with 1 and 0 respectively... can anyone show me how to do it without having to create a temp table? this is what i've got so far...


create table #tempLRM
([Key] varchar(100) COLLATE SQL_Latin1_General_CP1_CI_AS null,
[Start Date] datetime null);


insert into #tempLRM
select [key], min([start date])
from ReportDataLRM
group by [key];

update ReportDataLRM
set multi = 0
from #tempLRM t
where ReportDataLRM.[key]= t.[key]
and ReportDataLRM.[start date] = t.[start date];

update ReportDataLRM
set multi = 1
where multi is null;

select * from ReportDataLRM