I am trying to query JPA with Querydsl (4.1.4) as written here
http://www.querydsl.com/static/querydsl/latest/reference/html/ch02.html#jpa_integration . I use Hibernate (5.2.12.Final) as the JPA backend. I generate Querydsl query types from the JPA annotated classes using the apt-maven-plugin with the com.querydsl.apt.jpa.JPAAnnotationProcessor processor.
I have an issue while updating an entity : the updated value does not show up in the Java code. Here is the relevant code snippet that updates a boolean property (named success) in the Entity :
final EntityManagerFactory entityManagerFactory = PersistenceTestUtils.buildEntityManagerFactory();
final EntityManager entityManager = entityManagerFactory.createEntityManager();
final EntityTransaction transaction = entityManager.getTransaction();
transaction.begin();
final QJpaUpdateRound qJpaUpdateRound = QJpaUpdateRound.jpaUpdateRound;
final JPQLQueryFactory queryFactory = new JPAQueryFactory(entityManager);
final QJpaUpdateRound qJpaUpdateRound = QJpaUpdateRound.jpaUpdateRound;
final JPQLQueryFactory queryFactory = new JPAQueryFactory(entityManager);
final long roundId = 3L;
System.out.println("Original " +originalRound);
queryFactory //
.update(qJpaUpdateRound) //
.set(qJpaUpdateRound._success, true) //
.where(qJpaUpdateRound._id.eq(roundId)) //
.execute();
// entityManager.clear(); // Workaround
// Fetch the updated value
final UpdateRound updatedRound = queryFactory //
.selectFrom(qJpaUpdateRound) //
.where(qJpaUpdateRound._id.eq(roundId)) //
.fetchOne();
transaction.commit();
System.out.println("Updated "+ updatedRound);
This prints :
Original JpaUpdateRound{id=3; instant=2017-11-06T19:27:01.141Z; success=false}
Updated JpaUpdateRound{id=3; instant=2017-11-06T19:27:01.141Z; success=false}
Also, an identity test on originalRound and updatedRound shows that both variables are the same instance.
I checked in the database : the value is really updated. And if I uncomment the following line
entityManager.clear(); // Workaround
The program prints
Original JpaUpdateRound{id=3; instant=2017-11-06T19:39:01.038Z; success=false}
Updated JpaUpdateRound{id=3; instant=2017-11-06T19:39:01.038Z; success=true}
which is the result I expect.
It seems that the entity cache does not get updated when the Querydsl update is performed. Thus, it only returns the original Java object.
Why ? How can I synchronize the JPA backend and Querydsl ?
