继续求助!

这个题好玩

proc sort data=aaa out=bbb;
by sid xm descending VisitName ;
run;

data ccc;
set bbb;
if substr(strip(visitname),3,1)='_'
then a=value;
b=lag(a);
if b ne . then value=b;
drop a b;
run;

一个人的指标同一个访视有多个测量？可以用SQL并回去，并的条件视VisitName内容而定。

proc sql undo_policy=none;
        create table a as
                select a.*,b.value as value_1
                from aaa as a
                left join aaa(where=(index(VisitName,"_"))) as b
                on a.SID=b.SID and a.XM=b.XM and a.VIsitName=scan(b.VisitName,1,'_')
        ;
quit;
data a;
        set a;
        if ^missing(value_1) then value=value_1 ;
        drop value_1;
run;