proc sql noprint;
create table result2 as
select *
                ,sum(price*multi)/sum(price) as answer
from data2
group by label
;
quit;

label是标签，multi是乘数

Above Data step method is not correct.  Please see following code.


proc sort data=source;
by label;
run;

data main;
        set source;
        by label;
        retain fenzi_sum 0  fenmu_sum 0;
        if first.label then do;
                fenzi_sum = price*multi;
                fenmu_sum = price;
        end;
        if not first.label then do;
                fenzi_sum= fenzi_sum + price*multi;
                fenmu_sum = fenmu_sum + price;
        end;
        if last.label then do;
                answer = fenzi_sum/fenmu_sum;
                output;
        end;
run;

proc sort data=main; by label ; run;

data final;
        merge source  main(keep=label answer);
        by label;
run;

In summary, proc sql and data step are all fine with this problem. Proc sql looks even simpler.