Run Macro inside data _NULL_ - sas

Question

I have this data,
and I want to update a certain table using a macro
DATA WORK.t1;
LENGTH
POLICY_RK 8
POLICY_VERSION 8
TREATMENT_IND 8 ;
FORMAT
POLICY_RK BEST12.
POLICY_VERSION BEST12.
TREATMENT_IND BEST12. ;
INFORMAT
POLICY_RK BEST12.
POLICY_VERSION BEST12.
TREATMENT_IND BEST12. ;
INFILE DATALINES4
DLM='7F'x
MISSOVER
DSD ;
INPUT
POLICY_RK : BEST32.
POLICY_VERSION : BEST32.
TREATMENT_IND : BEST32. ;
DATALINES4;
105000002
114000005
123000007
132000001
141000007
1508
;;;;
I'm trying to run the below code:
%macro storno (pol_rk , pol_ver );
PROC SQL;
UPDATE t1
SET POLICY_VERSION=POLICY_VERSION*3.1113
where POLICY_RK=&pol_rk and policy_Version = &pol_ver;
QUIT;
%mend ;
data _null_;
set t1 ;
IF input(TREATMENT_IND,best12.) eq 1 THEN do;
call symputx("a",policy_rk);
call symputx("b",pol_ver);
end;
%storno(&a, &b);
%put a=&a;
%put b=&b;
run;
but get a warning message:
WARNING: Apparent symbolic reference A not resolved.
WARNING: Apparent symbolic reference B not resolved.
NOTE: Numeric values have been converted to character values at the places given by: (Line):(Column).
19:21
NOTE: There were 6 observations read from the data set WORK.T1.
NOTE: DATA statement used (Total process time):
real time 0.00 seconds
cpu time 0.00 seconds
NOTE: No rows were updated in WORK.T1.
What exactly am I doing wrong here....?

Answer 1

CALL SYMPUTX assigns values to macro variables, but those macro variables aren't available for use until after the end of the DATA step in which they're assigned.
That's because macro language compiles before the results of the data step. So SAS sees your call to %storno(&a, &b) before it processes the DATA step to assign the macro variables &a and &b.
See the "Problem Trying to Reference..." subsection of this link for more: https://support.sas.com/documentation/cdl/en/mcrolref/61885/HTML/default/viewer.htm#a000210266.htm
That's why you're seeing warnings about the symbolic references not being resolved - they don't exist yet when you're trying to use them.

Answer 2

Another good solution to running this - often better, IMO, because there are a few weird consequences of CALL EXECUTE that can affect how macros called from it work vs. called in plain code - is SELECT INTO.
proc sql;
select cats('%storno(',policy_rk,',',pol_ver,')') into :calllist separated by ' '
from t1
where input(TREATMENT_IND,best12.) eq 1
;
quit;
&calllist;
That pulls a list of calls into a macro variable (&calllist) and then runs them in open text just as if you'd run them separately.
You also ought to unwrap the PROC SQL if possible; it's adding a bit of extra overhead to open/close PROC SQL so many times.
Remove the PROC SQL and QUIT from the macro, then call it like this:
proc sql;
&calllist;
quit;