你指的观测是什么的观测？

    data aaa;
    input x y;
    cards;
    1 2
    3 4
    ;
    run;

    data bbb;
            set aaa;
            where x>3;
    run;

        proc sql noprint;
        select count(*) into: count1 from bbb;
        quit;
%macro count;
%if &count1 = 0 %then %do;
data _null_;
%put 'there is no observation in data set bbb';
run;
%end;
%else %do;
proc print data=bbb;
run;
%end;
%mend;
%count

data _null_;
      if _n_=0 then set bbb nobs=nobs;
     if nobs=0 then put 'bbb dataset has no observation';
     stop;
run;