Asignar a un campo un select max

[fredo]

tienes que poner u codigo en ibquery

'select max(item_prod) as mayor from prod '

luego abrela....
y por ultimo





procedure TForm6.Button1Click(Sender: TObject);
begin
ibquery.close;
ibquery.open;
band := DBLookupComboBox1.KeyValue;
IBDataSet1.Append;
DBLookupComboBox1.KeyValue := band;
IBDataSet1.FieldByName('item_prod').AsInteger := ibquery.fieldbyname('mayor'). asInteger;
end;