data ex;
input a $ b@@;
datalines;
101           2

002           3

101          3

101           4

104          1

002           10

104          5    

;
run;
proc sort data=ex;
by a;
run;
proc means data=ex;
by a;
var b;
output out=ex2 sum=btatol;
run;

data ex;
input a $ b@@;
datalines;
101 2
002 3
101 3
101 4
104 1
002 10
104 5
;

 
proc sql;
   select a, sum(b) as btotal
   from ex
   group by a;
   quit;

clarity

应该说用PROC SQL实现效果更好,系统的效率更高