Date:         Tue, 27 Jan 1998 12:11:02 -0500
Reply-To:     Carlos Garces <Carlos_Garces@IVAX.COM>
Sender:       "SAS(r) Discussion" <SAS-L@UGA.CC.UGA.EDU>
From:         Carlos Garces <Carlos_Garces@IVAX.COM>
Content-type: text/plain; charset=us-ascii

Dear SAS-L experts,
 
 I don't know what is happening, but maybe some of the SAS
  gurus could help me out.  I've simplified the code so it
  is easier to follow:
 
%MACRO HARDCODE(ID,VARIABLE,OLDVAL,NEWVAL);
 IF PAT=&ID AND &VARIABLE=&OLDVAL THEN DO;
    PUT 'PREVIOUS ' PAT=  &VARIABLE=;
    &VARIABLE=&NEWVAL;
    PUT 'NEW VALUE ' PAT= &VARIABLE=;
 END;
 ELSE IF PAT=&ID THEN DO;
    PUT "CONDITION FOR " PAT= " NOT MET - OLD VALUE: &OLDVAL - CURRENT
VALUE: " &VARIABLE=;
 END;
%MEND;
 
data pistart;
  do pat=630 to 640;
    output;
  end;
 
data temp;
 do pat=865 to 882;
   update='27JAN98'D;
   output;
  FORMAT UPDATE MMDDYY8.;
  end;
 
data pistart;
  set pistart temp;
%HARDCODE(635,update,.,'27jan98'd);
run;
 
 If you see the output below, you will notice that
  the value for variable UPDATE is retained!
 
  This doesn't happen if I use a 'by pat' statement.  I also
  cannot replicate this situation if I use an IF statement
  instead of the macro.
 
proc print data=pistart;
run;
 
              OBS    PAT      UPDATE
 
                1    630           .
                2    631           .
                3    632           .
                4    633           .
                5    634           .
                6    635    01/27/98
                7    636    01/27/98
                8    637    01/27/98
                9    638    01/27/98
               10    639    01/27/98
               11    640    01/27/98
               12    865    01/27/98
               13    866    01/27/98
               14    867    01/27/98
               15    868    01/27/98
               16    869    01/27/98
               17    870    01/27/98
               18    871    01/27/98
               19    872    01/27/98
               20    873    01/27/98
               21    874    01/27/98
               22    875    01/27/98
               23    876    01/27/98
               24    877    01/27/98
               25    878    01/27/98
               26    879    01/27/98
               27    880    01/27/98
               28    881    01/27/98
               29    882    01/27/98