proc sql;

create table nong1 as select a.dx_name, count(a.dx_name) as freq,mean(los) as ALOS, mean(charge) as a_charge, mean(paid) as a_paid from

nong as a where a.hos_id<=200

group by a.dx_name;
quit;

如题，看不明为这么多的AS分隔是什么意思？不能直接用一个AS在后面直接写上这些变量吗？谢谢了！