关于使用compute实行分类统计的问题

Question

procedure tuser.setrepotr();
 var
   low,hight:string;
   year,month,day,year1,month1,day1:word;
begin
      low:=formatdatetime('mm''/''dd''/''yy',datetimepicker1.Date);
      hight:=formatdatetime('mm''/''dd''/''yy',datetimepicker2.Date);
       with baobiao.Query1 do
        begin
         close;
         sql.Clear;
         sql.Add('select vipid,vipname,xfje,xfsj ');
         sql.Add('from trade ');
         sql.Add('where  xfsj>='+'#'+low+'#'+'and xfsj<='+'#'+hight+'#  ');
         sql.Add('order by vipid ');
         sql.Add('COMPUTE  SUM(xfje) by vipid');
       try
        open;
       except
         execsql;
         end;     //end try;
   end;           //end with;运行时说在 “ 语法错误（操作符丢失）在查询表达式‘vipid COMPUTE  SUM(xfje) by vipid’“请大哥们急急赐教!!!!!!!给50分！！！！！！！！！！！