data a;
input x y$;
cards;
1 d
2 kl
3 g
5 t
;
run;
data b;
input x z$;
cards;
1 k
2 f
4 hg
;
run;
data c_c;
merge a b;
by x;
run;
proc sql;
create table c as
select coalesce(a.x, b.x) as x, y ,b.z  
from a full join b  corr
on a.x=b.x;
quit;

请教大神有没有比我这个proc sql 更好的方法等价于 data c_c 了？？
想知道去掉coalesce的方法？