Question

我有两个给定的表（posgres），其中包含以下字段（所有大的整数）：

交易：

的transactionId
reader_id
readertrxref
...

冲销：

reversalid
trxref
readerid
...

交易和逆转之间存在可选的1：1关系：交易总是存在;如果交易已被撤销，则存在逆转。该关系是使用反转中的复合外键（reader_id，trxref）完成的。这些表是这样给出的，我需要在JPA中映射它们。我需要在Transaction中映射Reversal，我可以在命名查询中导航，即SELECT FROM Transaction t LEFT JOIN t.reversal rv ....

所以我所做的是：

@Entity
@Table(
        indexes = {
                @Index(columnList = "readerTrxRef,reader_id", unique = true),
        }
)
public class Transaction
{
    static final Long serialVersionUID = 1L;

    @Id
    @GeneratedValue
    private Long transactionid;

    private Long reader_id;

    private Long readertrxref

    @OneToOne(fetch = FetchType.EAGER, mappedBy = "transaction")
    private Reversal reversal;

    ...
}

@Entity
@Table(
        indexes = {
                @Index(columnList = "readerID,trxRef", unique = true),
        }
)
public class Reversal
{
    static final Long serialVersionUID = 1L;

    @Id
    @GeneratedValue
    private Long id;

    private Integer trxref;

    private Long readerid;

    public Integer getTrxRef()
    {
        return trxRef;
    }

    @OneToOne
    @JoinColumns(
            {
                    @JoinColumn(updatable = false, insertable = false, name = "readerid", referencedColumnName = "reader_id"),
                    @JoinColumn(updatable = false, insertable = false, name = "trxref", referencedColumnName = "readertrxref"),
            }
    )
    private Transaction transaction;

在部署期间，我收到以下异常：

14:24:12,455 ERROR [org.jboss.msc.service.fail] (ServerService Thread Pool -- 24) MSC000001: Failed to start service jboss.persistenceunit."ROOT.war#primary": org.jboss.msc.service.StartException in service jboss.persistenceunit."ROOT.war#primary": javax.persistence.PersistenceException: [PersistenceUnit: primary] Unable to build Hibernate SessionFactory
    at org.jboss.as.jpa.service.PersistenceUnitServiceImpl$1$1.run(PersistenceUnitServiceImpl.java:179)
    at org.jboss.as.jpa.service.PersistenceUnitServiceImpl$1$1.run(PersistenceUnitServiceImpl.java:121)
    at org.wildfly.security.manager.WildFlySecurityManager.doChecked(WildFlySecurityManager.java:667)
    at org.jboss.as.jpa.service.PersistenceUnitServiceImpl$1.run(PersistenceUnitServiceImpl.java:193)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
    at org.jboss.threads.JBossThread.run(JBossThread.java:320)
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: primary] Unable to build Hibernate SessionFactory
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.persistenceException(EntityManagerFactoryBuilderImpl.java:954)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:882)
    at org.jboss.as.jpa.hibernate5.TwoPhaseBootstrapImpl.build(TwoPhaseBootstrapImpl.java:44)
    at org.jboss.as.jpa.service.PersistenceUnitServiceImpl$1$1.run(PersistenceUnitServiceImpl.java:161)
    ... 7 more
Caused by: org.hibernate.MappingException: broken column mapping for: reversal.transaction of: ch.microtronic.evending.web.model.entities.Transaction
    at org.hibernate.persister.entity.AbstractPropertyMapping.initPropertyPaths(AbstractPropertyMapping.java:165)
    at org.hibernate.persister.entity.AbstractPropertyMapping.initIdentifierPropertyPaths(AbstractPropertyMapping.java:253)
    at org.hibernate.persister.entity.AbstractPropertyMapping.initPropertyPaths(AbstractPropertyMapping.java:219)
    at org.hibernate.persister.entity.AbstractEntityPersister.initOrdinaryPropertyPaths(AbstractEntityPersister.java:2194)
    at org.hibernate.persister.entity.AbstractEntityPersister.initPropertyPaths(AbstractEntityPersister.java:2241)
    at org.hibernate.persister.entity.AbstractEntityPersister.postConstruct(AbstractEntityPersister.java:3790)
    at org.hibernate.persister.entity.SingleTableEntityPersister.<init>(SingleTableEntityPersister.java:437)
    at sun.reflect.GeneratedConstructorAccessor62.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at org.hibernate.persister.internal.PersisterFactoryImpl.createEntityPersister(PersisterFactoryImpl.java:96)
    at org.hibernate.persister.internal.PersisterFactoryImpl.createEntityPersister(PersisterFactoryImpl.java:77)
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:346)
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:444)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:879)
    ... 9 more

有人能指出我的错吗？我只是尝试删除@JoinColumns并只有一个@JoinColumn。在这种情况下，我可以部署应用程序 - 这告诉我这是一个奇怪的错误，我不是很惊讶，如果它是一个hibernate的错误，即使我认为这是一个不是非常奇特的用例。（我们在Wildfly 10.1.0中使用Hibernate 5.2.12。）

编辑澄清映射是事务（reader_id，readertrxref） - ＆gt; reversal（readerid，trxref）并且这是以这种方式给出的。我需要以这种方式映射它，并且我不能使用transactionid作为反转中的外键，因为它（由于技术原因）在此表中不存在。

Answer 1

使用主键表是联合的。在您的情况下，它将是以下：

@OneToOne
@JoinColumn(name = "transactionid")
private Transaction transaction;

@JoinColumns注释用于复合主键。

我建议阅读wikibooks。

Answer 2

无法解决这个问题。正如Tom和DN1所指出的，JoinColumns必须在PK上。因为它们不是我用例中的PK而且我不能使它们成为复合PK（因为关系Transaction-＆gt; Reversal是可选的，因此，我仍然需要一个真正的PK即transactionID），似乎不可能用JPA来解决这个问题。

断列映射：OneToOne单向，带有两个连接列

2 个答案: