coalesce once a condition is met

[asinusdk]

From the table below, if I want to make a variable that shows at least "1" in v1 as the same value,  

year	id	v1
1	1	0
2	1	0
3	1	0
1	2	0
2	2	0
3	2	1
1	3	0
2	3	1
1	4	0
2	4	0
3	4	0

looks like this

year	id	v1	v2
1	1	0	0
2	1	0	0
3	1	0	0
1	2	0	1
2	2	0	1
3	2	1	1
1	3	0	1
2	3	1	1
1	4	0	0
2	4	0	0
3	4	0	0

How can I simply make a code?

Last time, I used first and last function, but it made too many datasets. 

I think coalesce in proc sql can do something, but I don't know how to do it...

Could you please help me?

[novinosrin · Accepted solution]

it's a straight forward proc sql 

data have;
input year id	v1;
cards;
1	1	0
2	1	0
3	1	0
1	2	0
2	2	0
3	2	1
1	3	0
2	3	1
1	4	0
2	4	0
3	4	0
;

proc sql;
create table want as
select *,max(v1) as v2
from have
group by id
order by id,year;
quit;

[asinusdk]

Thank you very much. I'm learning from you a lot. Have a good day.

[novinosrin]

as usual some fun

data have;
input year id	v1;
cards;
1	1	0
2	1	0
3	1	0
1	2	0
2	2	0
3	2	1
1	3	0
2	3	1
1	4	0
2	4	0
3	4	0
;

data want;
merge have have(rename=(v1=_iorc_) where=(_iorc_=1) keep=id v1);
by id;
v2=_iorc_>.;
run;