否 双方的关系(......) 我看不到什么话说这是无效的,但似乎在持续期间,至少一方的关系必须受到侵犯。 (例如,如果写作changeEntry first,changeEntryDetails将暂时取消。)

这种做法是有效的,所有东西都与经过适当规划的实体合作。 你们需要宣布你双向协会的一方为“拥有”一方(这种“控制”插入顺序)。 一种可行的解决办法:

@Entity
@NamedQueries( { @NamedQuery(name = ChangeEntry.FIND_ALL_CHANGEENTRIES, query = "SELECT c FROM ChangeEntry c") })
public class ChangeEntry implements Serializable {
    public final static String FIND_ALL_CHANGEENTRIES = "findAllChangeEntries";

    @Id
    @GeneratedValue
    private Long id;

    @OneToOne(optional = false, cascade = CascadeType.ALL)
    @JoinColumn(name = "DETAILS_ID", unique = true, nullable = false)
    @NotNull
    private ChangeEntryDetails changeEntryDetails;

    public void addDetails(ChangeEntryDetails details) {
        this.changeEntryDetails = details;
        details.setChangeEntry(this);
    }

    // constructor, getters and setters
}

http://java.sun.com/javaee/6/docs/api/javax/persistence/One ToOne.html#mappedBy%2829”rel=“noreferer”>。 属于非社团的归属:

@Entity
public class ChangeEntryDetails implements Serializable {
    @Id
    @GeneratedValue
    private Long id;

    @OneToOne(optional = false, mappedBy = "changeEntryDetails")
    @NotNull
    private ChangeEntry changeEntry;

    // constructor, getters and setters
}

与这些实体一起进行下列测试(为示范目的):

public class ChangeEntryTest {
    private static EntityManagerFactory emf;    
    private EntityManager em;

    @BeforeClass
    public static void createEntityManagerFactory() {
        emf = Persistence.createEntityManagerFactory("TestPu");
    }    
    @AfterClass
    public static void closeEntityManagerFactory() {
        emf.close();
    }    
    @Before
    public void beginTransaction() {
        em = emf.createEntityManager();
        em.getTransaction().begin();
    }    
    @After
    public void rollbackTransaction() {   
        if (em.getTransaction().isActive()) {
            em.getTransaction().rollback();
        }
        if (em.isOpen()) {
            em.close();
        }
    }

    @Test 
    public void testCreateEntryWithoutDetails() {
        try {
            ChangeEntry entry = new ChangeEntry();
            em.persist(entry);
            fail("Expected ConstraintViolationException wasn t thrown.");
        } catch (ConstraintViolationException e) {
            assertEquals(1, e.getConstraintViolations().size());
            ConstraintViolation<?> violation = e.getConstraintViolations()
                .iterator().next();

            assertEquals("changeEntryDetails", violation.getPropertyPath()
                .toString());
            assertEquals(NotNull.class, violation.getConstraintDescriptor()
                .getAnnotation().annotationType());
        }
    }

    @Test
    public void testCreateDetailsWithoutEntry() {    
        try {
            ChangeEntryDetails details = new ChangeEntryDetails();
            em.persist(details);
            fail("Expected ConstraintViolationException wasn t thrown.");
        } catch (ConstraintViolationException e) {
            assertEquals(1, e.getConstraintViolations().size());
            ConstraintViolation<?> violation = e.getConstraintViolations()
                .iterator().next();

            assertEquals("changeEntry", violation.getPropertyPath()
                .toString());
            assertEquals(NotNull.class, violation.getConstraintDescriptor()
                .getAnnotation().annotationType());
        }
    }

    @Test
    public void validEntryWithDetails() {
        ChangeEntry entry = new ChangeEntry();
        ChangeEntryDetails details = new ChangeEntryDetails();
        entry.addDetails(details);
        em.persist(entry);

        Query query = em.createNamedQuery(ChangeEntry.FIND_ALL_CHANGEENTRIES);
        assertEquals(1, query.getResultList().size());
    }
}

由于你的士官学校类型,它应当保持瞬间价值。

如果在你确定另一个瞬间因素之前,你实际上试图坚持第一个要素,那么你会期望出现这一错误。

你提出的制约因素只是具体指出,在数据库中,而不是在数据模型中,当你为新目的树立了一个榜样时,这一提法将是无效的。 虽然这一提法无效,但不能坚持该实体。

如果你在座与openJPA和Pascals 解决办法没有为你工作,你可能想将开放式JPA的房产( openjpa. InverseManager至true留守。