data a;
input name $ nation $ sex $ education $;
cards;
a china man under
b Ame woman grd
;
run;
data b;
input name $ id $ oldvalue $ newvalue $;
cards;
a sex man woman
b nation china Ame
;
run;
data c;
merge a b;
by name;
run;
data d;
set c;
if oldvalue eq nation then nation=newvalue;
else if oldvalue eq sex then sex=newvalue;
else if oldvalue eq education then education=newvalue;
run;