Concatenated where conditional in SAS - sas

Question

I am trying to write a macro to perform a proc summary operation on a dataset.
This macro takes in a few variables:
lower bound date (start = '01Jan2013'd)
upper bound date (end = '01Jan2016'd)
an additional 'and' condition (sometimes '', sometimes 'and state = XXX')
These variables are fed into the where statement in the macro below. Note that there will sometimes be an 'and' condition, and sometimes not at all.
%macro program1(start,end,cond); %macro _(); %mend _;
proc summary data = data1 nway missing;
where &start. < month < &end. || &cond.;
class month_inc;
var var1 var2;
output out =summ_data1 sum=;
run;
%mend;
I am having trouble getting the macro variables to work correctly in the where statement. The || doesn't work.
I tried to use CATX like so:
where catx(' ',&start. le month_inc le &end.,&cond.);
And that works to an extent. The &start. and &end. variables resolves as numerical values instead of the SAS dates, thus not summarizing my results correctly.

Answer 1

If you literally pass in the keyword AND as part of the value of the parameter COND (cond=and state='XXX') then just remove the concatenation operator from your WHERE statement.
where (&start<month<&end) &cond ;
Otherwise use macro logic to conditionally generate the part that references the optional COND value.
I like to use the WHERE ALSO (also known as where and) statement to augment existing WHERE statements.
%macro program1(start,end,cond);
proc summary data = data1 nway missing;
where &start. < month < &end. ;
%if %length(&cond) %then %do;
where also &cond.;
%end;
class month_inc;
var var1 var2;
output out =summ_data1 sum=;
run;
%mend;
So then your example call could look like this:
%program1(start = '01Jan2013'd
,end = '01Jan2016'd
,cond = state = 'XXX')