If - then - else is fulfilling both criterias

[StaceyB]

I have the following code with an if-then-else statement.  Both the If and the Else are running.  The value of &nrows being input to this dataset = 1 which meets the IF condition.  I know the Else is running because after the code executes "cancel" = the value from the Else do statement.

data _NULL_;
     if 0 then set specs_step2 nobs=n;
          if &nrows > 0 then do;
               %put NOTE: Program terminated because there are missing IRNs in the data.;
               %put See the Results or Output window for the cases where these are needed.;
               %put Putstate3 = There are &nrows. IRNs to update.;
               %let cancel = cancel;
          end;
          else do;
               %put NOTE: Continue processing. All IRNs are provided in the dataset.;
               %let cancel = This is the else condition;
          end;
          stop;
run;
%put Cancel = &cancel. ;

[Astounding]

Macro language statements such as %PUT and %LET are never part of a DATA step.  They cannot be controlled using DATA step IF THEN statements.

A DATA step can use PUT statements (not %PUT) to write messages, and can use CALL SYMPUTX to assign values to macro variables.

[StaceyB]

I did have the idea that I was mixing  up the macros with the data step.  I've been changing it around in all different ways. 

I will update to put instead of %put and will change the let statement to symputx.  

Thanks!

[Reeza]

You're mixing macro and data step logic and I have no idea where &nrows comes from. Maybe explain what you're trying to do and we can offer suggestions on how to accomplish that.

[StaceyB]

Okay, it's still not quite working.  

In a previous step in the code I'm setting the value of the &nrows.  Now I'd like to set the value of &cancel to either a blank or to the value of cancel and write to the log the corresponding put statements in the code above.  In the following statements I end them with:

run &cancel;  By doing this the remaining code doesn't run based on the value that was in &nrows at the point I'm placing the code in this post.

Does that help a little bit?

[Reeza · Accepted solution]

Do you just wan this then:

        %if &nrows > 0 %then %do;
               %put NOTE: Program terminated because there are missing IRNs in the data.;
               %put See the Results or Output window for the cases where these are needed.;
               %put Putstate3 = There are &nrows. IRNs to update.;
               %let cancel = cancel;
          %end;
          %else %do;
               %put NOTE: Continue processing. All IRNs are provided in the dataset.;
               %let cancel = This is the else condition;
            %end;

---

@StaceyB wrote:

Okay, it's still not quite working.  

In a previous step in the code I'm setting the value of the &nrows.  Now I'd like to set the value of &cancel to either a blank or to the value of cancel and write to the log the corresponding put statements in the code above.  In the following statements I end them with:

run &cancel;  By doing this the remaining code doesn't run based on the value that was in &nrows at the point I'm placing the code in this post.

Does that help a little bit?

---

[StaceyB]

Perfect.  Thank you.

[Tom]

So you have NROWS macro variable and you want to create CANCEL macro variable.

You can do that with macro code.

%if &nrows > 0 %then %do;
  %let cancel=cancel;
%end;
%else %do;
  %let cancel=;
%end;

If you are not running this inside a macro (or are using an old version of SAS that does not support %IF in open code) you could use a data step instead.

%let cancel=;
data _null_;
  if &nrows > 0 then call symputx('cancel','cancel');
run;

Our use %sysfunc() to call the IFC() function.

%let cancel=%sysfunc(ifc(&nobs > 0,cancel,));