data SofaData;
  set sashelp.prdsal3;
  where product="SOFA"
    and date between "01mar1998"d and "30apr1998"d
    and state in ("California" "Florida");
  keep State Date Actual;
run;
proc print data=SofaData;
  title1 "Sofa Data (There is a duplicate for California in Mar98)";
run;
proc sort data=SofaData out=ByStateDate noduprecs;
  by State Date;
run;
proc print data=ByStateDate;
  where State="California";
  title1 "California remains intact";
run;
  * REMOVE DUPLICATES, SORTING BY ALL VARIABLES (explicit);
proc sort data=SofaData out=ByAllVars noduprecs;
  by State Date Actual;
run;
proc print data=ByAllVars;
  where State="California";
  title1 "Complete Duplicate is Removed";
run;