我有一个实体类付款，它具有实体类 PaymentMethod 与一对多关系。
现在，由于My PaymentMethod是主表。
所以我想保存付款而不影响主表PaymentMethod。
但是每次我保存付款时，都会在PaymentMethod中插入新行。我不知道为什么。
我正在使用SpringData保存。
Payment.java
@Entity
@Table(name="payment")
public class Payment implements Serializable {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
@ManyToOne(cascade={CascadeType.REFRESH,CascadeType.MERGE,CascadeType.PERSIST})
@JoinColumn(name="payment_method_id")
private PaymentMethod paymentMethod;
//getter and setters
}
PaymentMethod.java
@Table(name="paymentmethod")
public class PaymentMethod implements Serializable {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
@Column(name="name",unique=true ,nullable=false)
private String name;
//GETTER AND SETTERS
}
PAYMENT_METHOD数据
ID | NAME
1 | AA
2 | BB
3 | CC
付款后保存
名称重复的PAYMENT_METHOD条目？
我不知道为什么？
为了节省，我为付款类型创建了简单的CRUDRepository
调用存储库的保存实体。
请建议我在哪里摔倒。
每当代码执行此行时:
paymentMethodRepository.findByName(payment.getPaymentMethod().getName());
它给出错误为
Caused by: org.hibernate.TransientPropertyValueException: object references an unsaved transient instance - save the transient instance before flushing: com.enrollment.domain.Payment.paymentMethod -> com.enrollment.domain.PaymentMethod
at org.hibernate.engine.spi.CascadingAction$8.noCascade(CascadingAction.java:380)
at org.hibernate.engine.internal.Cascade.cascade(Cascade.java:176)
at org.hibernate.event.internal.AbstractSaveEventListener.cascadeBeforeSave(AbstractSaveEventListener.java:423)
at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:264)
at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:193)
at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:136)
at org.hibernate.ejb.event.EJB3PersistEventListener.saveWithGeneratedId(EJB3PersistEventListener.java:78)
at org.hibernate.event.internal.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:208)
at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:151)
at org.hibernate.internal.SessionImpl.firePersistOnFlush(SessionImpl.java:870)
at org.hibernate.internal.SessionImpl.persistOnFlush(SessionImpl.java:863)
at org.hibernate.engine.spi.CascadingAction$8.cascade(CascadingAction.java:346)
at org.hibernate.engine.internal.Cascade.cascadeToOne(Cascade.java:380)
at org.hibernate.engine.internal.Cascade.cascadeAssociation(Cascade.java:323)
at org.hibernate.engine.internal.Cascade.cascadeProperty(Cascade.java:208)
at org.hibernate.engine.internal.Cascade.cascadeCollectionElements(Cascade.java:409)
at org.hibernate.engine.internal.Cascade.cascadeCollection(Cascade.java:350)
at org.hibernate.engine.internal.Cascade.cascadeAssociation(Cascade.java:326)
at org.hibernate.engine.internal.Cascade.cascadeProperty(Cascade.java:208)
at org.hibernate.engine.internal.Cascade.cascade(Cascade.java:165)
at org.hibernate.event.internal.AbstractSaveEventListener.cascadeAfterSave(AbstractSaveEventListener.java:448)
at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:293)
at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:193)
at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:136)
at org.hibernate.ejb.event.EJB3PersistEventListener.saveWithGeneratedId(EJB3PersistEventListener.java:78)
at org.hibernate.event.internal.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:208)
at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:151)
at org.hibernate.internal.SessionImpl.firePersistOnFlush(SessionImpl.java:870)
at org.hibernate.internal.SessionImpl.persistOnFlush(SessionImpl.java:863)
at org.hibernate.engine.spi.CascadingAction$8.cascade(CascadingAction.java:346)
at org.hibernate.engine.internal.Cascade.cascadeToOne(Cascade.java:380)
at org.hibernate.engine.internal.Cascade.cascadeAssociation(Cascade.java:323)
at org.hibernate.engine.internal.Cascade.cascadeProperty(Cascade.java:208)
at org.hibernate.engine.internal.Cascade.cascade(Cascade.java:165)
at org.hibernate.event.internal.AbstractSaveEventListener.cascadeAfterSave(AbstractSaveEventListener.java:448)
at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:293)
at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:193)
at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:136)
at org.hibernate.ejb.event.EJB3PersistEventListener.saveWithGeneratedId(EJB3PersistEventListener.java:78)
at org.hibernate.event.internal.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:208)
at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:151)
at org.hibernate.internal.SessionImpl.firePersistOnFlush(SessionImpl.java:870)
at org.hibernate.internal.SessionImpl.persistOnFlush(SessionImpl.java:863)
at org.hibernate.engine.spi.CascadingAction$8.cascade(CascadingAction.java:346)
at org.hibernate.engine.internal.Cascade.cascadeToOne(Cascade.java:380)
at org.hibernate.engine.internal.Cascade.cascadeAssociation(Cascade.java:323)
at org.hibernate.engine.internal.Cascade.cascadeProperty(Cascade.java:208)
at org.hibernate.engine.internal.Cascade.cascade(Cascade.java:165)
at org.hibernate.event.internal.AbstractSaveEventListener.cascadeBeforeSave(AbstractSaveEventListener.java:423)
at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:264)
at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:193)
at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:136)
at org.hibernate.ejb.event.EJB3PersistEventListener.saveWithGeneratedId(EJB3PersistEventListener.java:78)
at org.hibernate.event.internal.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:208)
at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:151)
at org.hibernate.internal.SessionImpl.firePersistOnFlush(SessionImpl.java:870)
at org.hibernate.internal.SessionImpl.persistOnFlush(SessionImpl.java:863)
at org.hibernate.engine.spi.CascadingAction$8.cascade(CascadingAction.java:346)
at org.hibernate.engine.internal.Cascade.cascadeToOne(Cascade.java:380)
at org.hibernate.engine.internal.Cascade.cascadeAssociation(Cascade.java:323)
at org.hibernate.engine.internal.Cascade.cascadeProperty(Cascade.java:208)
at org.hibernate.engine.internal.Cascade.cascade(Cascade.java:165)
at org.hibernate.event.internal.AbstractSaveEventListener.cascadeBeforeSave(AbstractSaveEventListener.java:423)
at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:264)
at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:193)
at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:136)
at org.hibernate.ejb.event.EJB3PersistEventListener.saveWithGeneratedId(EJB3PersistEventListener.java:78)
at org.hibernate.event.internal.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:208)
at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:151)
at org.hibernate.internal.SessionImpl.firePersistOnFlush(SessionImpl.java:870)
at org.hibernate.internal.SessionImpl.persistOnFlush(SessionImpl.java:863)
at org.hibernate.engine.spi.CascadingAction$8.cascade(CascadingAction.java:346)
at org.hibernate.engine.internal.Cascade.cascadeToOne(Cascade.java:380)
at org.hibernate.engine.internal.Cascade.cascadeAssociation(Cascade.java:323)
at org.hibernate.engine.internal.Cascade.cascadeProperty(Cascade.java:208)
at org.hibernate.engine.internal.Cascade.cascadeCollectionElements(Cascade.java:409)
at org.hibernate.engine.internal.Cascade.cascadeCollection(Cascade.java:350)
at org.hibernate.engine.internal.Cascade.cascadeAssociation(Cascade.java:326)
at org.hibernate.engine.internal.Cascade.cascadeProperty(Cascade.java:208)
at org.hibernate.engine.internal.Cascade.cascade(Cascade.java:165)
at org.hibernate.event.internal.AbstractFlushingEventListener.cascadeOnFlush(AbstractFlushingEventListener.java:160)
at org.hibernate.event.internal.AbstractFlushingEventListener.prepareEntityFlushes(AbstractFlushingEventListener.java:151)
at org.hibernate.event.internal.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:88)
at org.hibernate.event.internal.DefaultAutoFlushEventListener.onAutoFlush(DefaultAutoFlushEventListener.java:58)
at org.hibernate.internal.SessionImpl.autoFlushIfRequired(SessionImpl.java:1186)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1241)
at org.hibernate.internal.QueryImpl.list(QueryImpl.java:101)
at org.hibernate.ejb.QueryImpl.getSingleResult(QueryImpl.java:285)
当我从存储库中调用finder方法时，我无法弄清楚如何尝试刷新代码。
我缺少什么吗？
感谢@JB和@spiritwalker解决了问题，但无法找到确切的根本原因，因此仅讨论行为可能会使讨论变得过于了解。
Behaviour ..
Open Transaction
1. validate
2. save child
3. validate and update
4. save parent
Close Transaction
it was giving above error.
Now, after code change it worked
Open Transaction
1. validate
2. validate and update
3. save child
4. save parent
Close Transaction
最佳答案
首先删除级联，因为在创建/修改付款时，您恰恰不想创建/修改PaymentMethod。
然后，在创建付款时，为其分配要与之关联的现有PaymentMethod:
PaymentMethod existingPaymentMethod = em.find(PaymentMethod.class, idOfThePaymentMethod);
Payment payment = new Payment();
payment.setPaymentMethod(existingPaymentMethod);
em.persist(payment);
关于hibernate - @ManyToOne单向映射，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/14919726/