data x;         
input  id a;      
cards ;         
20090202 1   
20090404 2
;run;
         
data y;         
input id;      
cards;         
20090202     
;run;   
proc sql;
select * from x
where not exists
(select * from y where x.id=y.id)
;quit;

不错，还真得好好学学sql

thanks very much~~~

1# ningxia

*** method1  ***;
data a;
input id var1 var2;
datalines;
1 11 12
2 13 14
3 15 16
4 17 18
5 19 20
;

data b;
input id;
datalines;
1
3
4
;

proc sql;
create table dif AS
select *
from a
where id not in (select id from b)
;
quit;

*** method2 ***;
data dif;
  merge a (in=ain) b (in=bin);
  by id;
if ain=1 and bin=0;

proc print; id id; run;