SAS - which variables are missing from the data set in comparison to another data set

sas_variable_list_compare.sas

*create example data;
data class;
set sashelp.class;
run;

data class2;
set sashelp.class;
drop age sex;
run;

*set macro variables;
%let lib_master=work;
%let master=Class2;
%let lib_sub=work;
%let sub=Class;
%let dlm=" ";


*create a variable list of missing variables;
proc sql noprint;
select name into :drop_list separated &dlm.
from sashelp.vcolumn
where upper(libname)=upper("&lib_sub.") 
and upper(memname) = upper("&sub")
and name not in (select name 
                from sashelp.vcolumn 
                where upper(libname)=upper("&lib_master.") 
                and upper(memname) = upper("&master"));
quit;

*show results;
%put &drop_list;