problem with extending OrderLookupServices

[Jacek Wagner]

All,

I am extending findOrders (OrderLookupServices)  by adding  
OrderAttribute and Payment as searchable entities.

The OrderAttribute works as expected
       // search by child name
       if (UtilValidate.isNotEmpty(childName)) {
           dve.addMemberEntity("OA", "OrderAttribute");
           dve.addAlias("OA", "attrValue");
           dve.addViewLink("OH", "OA", Boolean.FALSE, 
UtilMisc.toList(new ModelKeyMap("orderId", "orderId")));
           paramList.add("attrValue=" + childName);
           conditions.add(makeExpr("attrValue", childName));
       }

but

       // search by payment ref number
       if (UtilValidate.isNotEmpty(paymentRefNum)) {
           dve.addMemberEntity("PT", "Payment");
           dve.addAlias("PT", "paymentRefNum");
           dve.addViewLink("OP", "PT", Boolean.FALSE, 
UtilMisc.toList(new ModelKeyMap("orderPaymentPreferenceId", 
"paymentPreferenceId")));
           paramList.add("paymentRefNum=" + paymentRefNum);
           conditions.add(makeExpr("paymentRefNum", paymentRefNum));
       }
returns message ..orderPaymentPreferenceId does not exist on the 
Payment entity.

Note: this is the case  where fields with  matching content 
(orderPaymentPreferenceId & paymentPreferenceId) have  different  names.

I am stuck with this otherwise piece of art code.

Please help.

Jacek