PDK PortalDataViewer "Could not retrieve data"

Hi all,

I try to access to a local mysql DB to render some data in a PortalDataViewer.

But I always get an errormessage: Could not retrieve data.

Here is the relevant part of the code:

******************************************

System.err.println(sss);

   Statement std = con.createStatement();

   ResultSet res = std.executeQuery("select * from company");

   /*while(res.next())

                        {

                            System.out.println(res.getString("cust_no"));

                        }*/

   con.close();

   ISource pdvSource = portalDV.createSource(request, res);

   portalDV.setSource(pdvSource);

***********************

The SQL statement is fine-when I outcomment the result- I get the data in the server output window.

But in the IView I get the errormessage Could not retrieve data.

Thanks for your help!