proc sql;
create table c as select a.id,b.grade from a b;
quit;

data a;
id=1;output;
id=4;output;
id=5;output;
id=8;output;
run;

data b;
grade="a";output;
grade="s";output;
grade="e";output;
grade="f";output;
run;


data c;
    set a ;
        do i=1 to  nobs;
           set b nobs=nobs point=i;
           output;
    end;
run;

proc sql;
create table c as select a.id,b.grade from a, b;
quit;