🚀 go-pugleaf

Hi,
sorry for asking so much :)

Can I make this onCalcFields event faster?

void __fastcall TDM::CDKundenlisteCalcFields(TDataSet *DataSet)
{
    if(DataSet->State == dsInternalCalc){
            QADIS->Close();
            QADIS->SQL->Text = "select max(Datum) as LBDatum from
Besuchsberichte where Kundennummer = " +
DataSet->Fields->FieldByName("Kundennummer")->AsString;
            QADIS->Open();
            DataSet->Fields->FieldByName("letzter Besuch")->AsDateTime =
Date();//QADIS->Fields->FieldByName("LBDatum")->AsDateTime;
    }
}

Any Idears?
I am not using Params because of performance.
When I make a lookup field to the same database and set the Keys
"Kundennummer = Kundennummer" it is very much faster than the calculated
field. I can not use the lookup field because Kundennummer is not unique and
I want to display the latest date with the max(Datum).
But why is the lookup field so fast? The lookupfield has to calculate the
field too and search the other database, didn�t it?

Thanks,
Joachim