No entity found for query Exception

Question

I am executing the following lines:

  String queString = \"some query string\"
  Query q1 = em.createNativeQuery(queString, T03CallsLog.class);
  T03CallsLog         


        

Answer 1

The error message usually tells you, that the query returned no result. And so getSingleResult() fails.

Consider using getResultList() and test the result with isEmpty() if you expect empty query results:

T03CallsLog newCall = null;
List results = q1.getResultList();
if (!results.isEmpty())
   newCall = (T03CallsLog) results.get(0);
else
   // is it a problem? -> log.

Answer 2

If a query returns no result, a NoResultException is thrown by getSingleResult(). Are you sure, the seconds MDB, will get any results by your query?

Answer 3

Hibernate

The more specific entityManager in hibernate is the HibernateEntityManager. If you instead of

@PersistenceContext
public final EntityManager em = null;

Use the more specific

@PersistenceContext
public final HibernateEntityManager em = null;

Then you could use the

String queString = "some query string"
Iterator<T03CallsLog> q1 = em.createNativeQuery(queString, T03CallsLog.class).iterate();
T03CallsLog newCall = q1.hasNext() ? q1.next() : null;