As mentioned in [ HHH-8487 ] flush to the database is always done before accessing an entity via native SQL or HQL query when FlushModeType.AUTO is enabled.
So the @Version annotated property is always incremented when an update / merge with fetch with SQL of an entity occurs.
But when doing an update to an entity and access it with {{entityManager.find( )}} the version is not incremented. So this behavior is inconsistent according to fetching over SQL.
Should a flush to the database not also be done when calling {{entityManager.find( )}}?
Consider the testcase below as example:
{code:java} package org.hibernate.bugs;
import org.apache.log4j.Logger;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import javax.persistence.*;
import java.util.List;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;
/**
* This template demonstrates how to develop a test case for Hibernate ORM, using the Java Persistence API.
*/
public class JPAUnitTestCase {
Logger LOG = Logger.getLogger(JPAUnitTestCase.class);
private EntityManagerFactory entityManagerFactory;
private EntityManager entityManager;
@Before
public void init() {
entityManagerFactory = Persistence.createEntityManagerFactory("templatePU");
entityManager = entityManagerFactory.createEntityManager();
// entityManager.setFlushMode(FlushModeType.COMMIT);
entityManager.setFlushMode(FlushModeType.AUTO);
}
@After
public void destroy() {
entityManager.close();
entityManagerFactory.close();
}
@Test
public void hhh123Test() throws Exception {
entityManager.getTransaction().begin();
TableB b = new TableB();
b.setName("name b");
b.setDescription("Bsome description");
entityManager.persist(b);
TableA a = new TableA();
a.setName("name a");
a.setDescription("some description");
entityManager.persist(a);
{
a.setDescription("some new description 1");
entityManager.merge(a);
TableA aFetch = entityManager.find(TableA.class, a.getId());
//version is not incremented, no flush
assertThat(aFetch.getVersion(), is(0L));
}
{
// flush is executed and version is incremented
Query query = entityManager.createQuery("select entity from table_a entity where id = :id").setParameter("id", a.getId());
TableA aFetch = (TableA) query.getSingleResult();
assertThat(aFetch.getVersion(), is(1L));
}
{
a.setDescription("some new description 2");
entityManager.merge(a);
TableA aFetch = entityManager.find(TableA.class, a.getId());
//version is not incremented, no flush
assertThat(aFetch.getVersion(), is(1L));
//do native query
List resultList = entityManager.createNativeQuery("select * from table_b", TableB.class).getResultList();
// flush is executed and version of TableA is incremented
TableB bFetch = (TableB) resultList.get(0);
assertThat(bFetch.getVersion(), is(0L));
aFetch = entityManager.find(TableA.class, a.getId());
assertThat(aFetch.getVersion(), is(2L));
}
LOG.info("Do commit");
entityManager.getTransaction().commit();
}
@Entity(name = "table_a")
public static class TableA {
@Version
@Column
private Long version;
@Id
@GeneratedValue
@Column(name = "oId", updatable = false, nullable = false)
private Long id;
@Column(nullable = true)
private String name;
@Column(nullable = true)
private String description;
public Long getVersion() {
return version;
}
public void setVersion(Long version) {
this.version = version;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
@Override
public String toString() {
return String.format("TableA{version=%d, id=%d, name='%s', description='%s'}", version, id, name, description);
}
}
@Entity(name = "table_b")
public static class TableB {
@Version
@Column
private Long version;
@Id
@GeneratedValue
@Column(name = "oId", updatable = false, nullable = false)
private Long id;
@Column(nullable = true)
private String name;
@Column(nullable = true)
private String description;
public Long getVersion() {
return version;
}
public void setVersion(Long version) {
this.version = version;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
@Override
public String toString() {
return String.format("TableB{version=%d, id=%d, name='%s', description='%s'}", version, id, name, description);
}
}
}
{code :java }
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