Need help on retrieving query result - NPE

Question

Hi, I could get results with the native query in my TOAD, but I can't get it working in my session EJB. I tried both native query and EJB ql. The query created fine, as soon as I try to retrieve results, it gets stuck.
My native query looks like this:
Query query = em.createNativeQuery("select sum(o.amount_reimbursed) from t_expenses o where o.employee_id = '999999911' " +
"and o.EXPENSE_ID in (select p.expense_id from T_Per_Diem_Xref p where p.expense_Type_Xref_Id=22 " +
"and p.expense_Id in (select e.expense_Id from T_Expenses e where e.employee_Id='999999911' " +
"and e.expense_date > to_date('01/01/2011', 'mm/dd/yyyy') and e.expense_date < to_date('12/31/2011', 'mm/dd/yyyy')))") ;
My EJB query looks like this:
Query query = em.createQuery("select sum(o.amountReimbursed) from TExpenses o where o.employeeId = ?1 " +
"and o.expenseId in (select p.expenseId from TPerDiemXref p where p.expenseTypeXrefId=?2 " +
"and p.expenseId in (select e.expenseId from TExpenses e where e.employeeId=?1 and e.expenseDate>=?3 and e.expenseDate<=?4))");
query.setParameter(1, employeeId);
query.setParameter(2, expenseType);
query.setParameter(3, fDay, TemporalType.TIMESTAMP);
query.setParameter(4, lDay, TemporalType.TIMESTAMP);
Either one, I get NPE at the line retrieve result.
// sumAmt = (Double)query.getSingleResult();
List list = query.getResultList();
if (list != null) {
long longAmt = (Long)list.get(0);
sumAmt = (Double)list.get(0);
As you can see, I tried to getSingleResult, or getResultList. also tried to convert the result to Double or Long. None worked.
Please help and thank you for your time.
Sophia

Answer 1

Frank, thank you for your reply. I have this code in my session Facade EJB, and I get the NPE in my backing bean which calls this method. When I debug the code, it appears what really cuases the problem is in this code on the line I try to assign the query result to my variable 'sumAmt = (Double)query.getSingleResult();'. In the debug, when it reaches this line, it starts to give me all kinds of pop-up windows saying couldn't find this file or that file or packages. If I get a stack trace later, I will post it. Right now I am trying to fix something else.
Thanks, Sophia