Delphi 7 Неправильно выполняется скрипт ADOQuery : Программирование

procedure TForm1.Button1Click(Sender: TObject);
var
  dt1, dt2 : TDateTime;
begin
ADOQuery1.Close;
ADOQuery1.SQL.Clear;
ADOQuery1.SQL.Add ('select SMCardSecurityLog.username as Оператор, Count(DISTINCT SMCardSecurityLog.article)AS Количество from SMCardSecurityLog where actioncode= :docstate and (eventtime between :date1 AND :date2) group by username');
dt1 := Trunc(DateTimePicker1.Date);
dt2 := Trunc(DateTimePicker2.Date);
ADOQuery1.Parameters.ParamByName('date1').Value:= dt1;
ADOQuery1.Parameters.ParamByName('date2').Value:= dt2;
ADOQuery1.Parameters.ParamByName('docstate').Value:=3;
ADOQuery1.Open;
end;

end.

select * from SMCardSecurityLog