Macro Loop

[BU2B]

Hey all,

I have a macro that I want to loop through a couple of variables (&CP_ID and &REP) and pass them to the program.  It works fine for the 1st iteration but never starts the 2nd etc...  What is my code missing?  Thanks!

proc sql noprint;
 select  CP_ID, REP into :CP_ID separated by ' ', :REP separated by ' '
   from crep2.crep_attributes;
quit;

%macro crep_rs;
 %let i = 1;
 %let YrMo = &YrMo;
 %let CP_ID = %scan(&CP_ID, &i);
 %let REP = %scan(&REP, &i);
 %do %until (&CP_ID=);
 
  A BUNCH OF VALID SAS CODE
  
  %let i = %eval(&i+1);
 %let CP_ID = %scan(&CP_ID,&i);
 %let REP = %scan(&REP,&i);
 %end;
 %mend;
%crep_rs;

[ndp · Accepted solution]

You are changing values for &CP_ID and &REP in the macro with statements:

%let CP_ID = %scan(&CP_ID, &i);
%let REP = %scan(&REP, &i);

create new macro variables:

%let _CP_ID = %scan(&CP_ID, &i);
%let _REP = %scan(&REP, &i); 

don't forget to change references eleswhere within the code.

[BU2B]

Thanks guys!  I really apreciate it.  have a good weekend...

Steve

[Astounding]

You're right, it won't work.  Here's the problem.

Consider this statement before the loop begins:

%let CP_ID = %scan(&CPI_ID, &i);

Before this statement, &CP_ID contained two words.  After the statement, it only contains one word.  So inside the %do %until loop, when you increment &i to 2, there is no longer a second word for %SCAN to locate within &CP_ID.

The solution is simple ... don't replace the two-word version of &CP_ID.  Assign each word to a new macro variable.

Good luck.