merge 2 data sets by char vars

[Ronein]

Hello

I want to merge 2 data sets by char vars.

This example is working well but in real world when I do it I don't succeed. merge the 2 tables well 

The field I want to add has null values (in real world)

Why???

  data abc1;
 infile datalines dlm=',';
length x1 $11 x2 $6 ;
 input x1 $ x2 $ ;
 cards;
 AGE_1_VALUE,YESHUT
 ;
 Run;

 data abc2;
 infile datalines dlm=',';
length x1 $11 x2 $6 x3 $10.;
 input x1 $ x2 $ x3 $ ;
 cards;
 AGE_1_VALUE,YESHUT,continuous
 ;
 Run;

proc sql;
create table want as
select a.*,b.x3
from abc1  as a
left join abc2 as b
on compress(upcase(a.x1))=compress(upcase(b.x1)) and compress(upcase(a.x2))=compress(upcase(b.x2))
;
quit;

[Kurt_Bremser]

Explain in detail what you mean by "don't succeed". Does it throw an ERROR/WARNING or is the result not what you expect?

Anyway, provide examples of the data where this happens.