How to test whether macro variable exist in macro if statement?

[afiqcjohari]

%macro extract(beginDate='01JAN2017'd,
	                        endDate='05JAN2017'd,
	                        cPvderVAR=);
%put &cPvderVAR.;
	data want_&cPvderVAR.;
		set have;
		%if '&cPvderVAR.' ne %then %do; 
			where dTran >= &beginDate. and dTran <= &endDate. and cPvder='&cPvderVAR.' ;
		%end;
		%else %do;
			where dTran >= &beginDate. and dTran <= &endDate.;
		%end;
	run;
%mend extract;

%extract(cPvderVAR=PING);

Keep getting this error

WHERE 0 /* an obviously FALSE WHERE clause */ ;

What I want is, if the macro variable cPvderVAR has a value then add the where statement with cPvder = &cPvderVAR. 

Note that cPvder is a string.

Does SAS has something to test whether the macro variable is of length null or positive?

[Shmuel · Accepted solution]

You defined the macro as: 

%macro extract(beginDate='01JAN2017'd, endDate='05JAN2017'd, cPvderVAR=);

I understand that you want to check does the 2nd argument is not empty,

then can use either %if  &cPvderVAR NE (without quotes)   or  %if %length(&cPvderVAR) > 0

You could alse use next code:

%macro extract(beginDate='01JAN2017'd,
	                        endDate='05JAN2017'd,
	                        cPvderVAR=);
%put &cPvderVAR.;
	data want_&cPvderVAR.;
		set have;
		%do;
			where dTran >= &beginDate. and dTran <= &endDate. 
                %end;
                %if &cPvderVAR. ne %then %do; 
                              and cPvder="&cPvderVAR."      /* changed to double quotes */ 
		%end;
                 ;    /* semicolon to close the where statement */
	run;
%mend extract;

%extract(cPvderVAR=PING);

[afiqcjohari]

I was trying to factor the common condititions but couldn't work it out. I'm glad you helped with it as well :). Thanks.

[Astounding]

You can't use single quotes around a reference to a macro variable.  It won't resolve.  Try it this way:

%macro extract (beginDate='01JAN2017'd, endDate='05JAN2017'd, cPvderVar=);

   %put &cPvderVAR.;

   data want_&cPvderVAR.;

      set have;

      where (&beginDate. <= dTran <= &endDate.)

      %if %length(&cPvderVar) %then and cPvder="&cPvderVAR.";

      ;

   run;

%mend extract;

%extract(cPvderVAR=PING)

Switching to double quotes lets &cPvderVAR resolve.  The other changes aren't mandatory, just coding that makes it easier to see how the program changes when cPvderVAR is specified vs. not specified.

[afiqcjohari]

That extra information about the single/double quote is helpful.