CODEWITHSUNDEEP
loopsmacrossassas-macrodo-loops
Charlotte Stevens
Charlotte Stevens

Reputation: 91

SAS Macro Do Loop not resolving

Can anybody tell me why this isn't resolving:

/*put all transaction table names into a data set*/ 
/*(table names are of format transac_20130603_20130610 (date from and date to)*/
data transaction_tables;
    set SASHELP.VTABLE (keep=libname memname);
    where lowcase(substr(memname,1,8))='transac_'

run;
/*sort and add rownumbers*/
proc sql;
create table transaction_tables as
    select *, monotonic() as rownum
         from transaction_tables
             order by memname;
run;
/*find rownumber of first and last transaction tables with run dates before campaign start and after end date of campaign*/
data _NULL_;
set transaction_tables;
    if substr(memname,9,8)<=&pre_period_start. and substr(memname,18,8)>=&pre_period_start. then do;
        call symput("r1", rownum);
        stop; 
        end;
run;        
data _NULL_;
set transaction_tables;
    if substr(memname,9,8)<=&max_enddate. and substr(memname,18,8)>=&max_enddate. then do;
        call symput("r2", rownum);
        stop;
        end;
run;
%put &r1; %put &r2;
/*r1 = 11, r2 = 27 - both resolving OK*/

/*get all relevant transaction table names where rownumbers are between r1 and r2*/
/*r1=11 and r2=27 so my transaction table name macros should run from t_0 to t_16/*
%macro trans;
%let y = %eval(&r2 - &r1);
%do i=0 %to &y;
data _NULL_;
set transaction_tables;
    if rownum = &r2 - (&r2 - &r1 - &i)  then do;
        call symput("t_&i", cats(libname, '.', memname));
        stop; 
        end;
%end;
%mend trans;
%trans;

%put &t_0;
--WARNING: Macro variable "&t_0" was not resolved

i'm not entirely sure why but from messing around with a few of the variables i think the problem lies with the last part where it is attempting to assign table names to t_&i macros. i think the issue is with trying to name a macro variable while trying to call another macro variable (trying to create macro t_0 by calling &i when i=0). i guess i've screwed something up with the syntax because i think the logic is fairly sound.

thanks!

Upvotes: 1

Views: 767

Answers (2)

Allan Bowe
Allan Bowe

Reputation: 12691

Alternative approach:

proc sql;                                                                                                                               
create table result as                                                                                                                  
    select cats(libname,'.',memname) as desired                                                                                                      
    from dictionary.tables                                                                                                                  
    where substr(libname,1,8)='TRANSAC_'     
    and (scan(libname,2,'_')<=&pre_period_start. and scan(libname,3,'_')>=&pre_period_start.) 
    and (scan(libname,2,'_')<=&max_enddate. and scan(libname,3,'_')>=&max_enddate.) ;

data _null_;
    set result;
    call symput(cats('R_',_n_),desired,'g');
run;

This could even be rewritten as one step using the SQL 'into' clause. The SQL quit; statement is optional, personally I never use it.

Upvotes: 1

mvherweg
mvherweg

Reputation: 1283

Without judging the usefulness of what you're trying to do:

It is a scope issue. Any macro variable you create within a macro, only exists within that macro. If you want it to exist outside your macro, you either need to:

  • Create the macro variable in open code (not in a macro) and before you execute the macro.

  • Set it explicitly to global within your macro (before the first mention of it), you do this by writing:

    %global t_0;

edit Also note that to end a proc sql, you need to use quit instead of run.

Upvotes: 1

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