data 步增加列的方法

shiyiming

data  dtic;
        set a (keep= end start to )
            b(keep= end start to ) ;
run;
表操作如上，怎样在data步中将不同表中的数据加以区分，如加上一个字段flag 如果在a表中则flag='01',在b表中则flag='02';
谢谢

shiyiming

[code:17mtgh0j]
data dtic;
set a (keep= end start to in=a)
b(keep= end start to in=b) ;
length flag $2;
if a then flag='01';
else if b then flag='02';
run;

[/code:17mtgh0j]

shiyiming

谢谢byes了