topic Re: Macro Loop in SAS Programming

Macro Loop

BU2B — Fri, 23 Oct 2015 16:01:28 GMT

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;

Re: Macro Loop

ndp — Fri, 23 Oct 2015 16:07:33 GMT

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.

Re: Macro Loop

Astounding — Fri, 23 Oct 2015 16:10:23 GMT

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.

Re: Macro Loop

BU2B — Fri, 23 Oct 2015 18:13:41 GMT

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

Steve