Hibernate jpa "mappedBy“异常

Question

当我想使用持久化方法向数据库中添加新的UserDetails对象时，我的JPA数据库出现了问题。然后我得到了异常：“密钥hibernate的重复条目2”--这个异常与Product有关。我找到了基于向@OneToMany (上面的Product列表)添加mappedBy参数的解决方案，但是我得到了"mappedBy引用一个未知的目标实体属性“，有解决方案吗？

@Entity
public class UserDetails {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private long id;

....
@OneToOne(cascade = CascadeType.ALL)
private UserOffer userOffer;
..... 
//getters and setters

下一首

@Entity
public class UserOffer {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private long id;

.....
@OneToOne(cascade= CascadeType.ALL)
private DetailsOffer detailsOffer;
.....

下一首

@Entity
public class DetailsOffer {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private long id;

@OneToMany(cascade = CascadeType.ALL, mappedBy="detailsOffer")
private List<Product> products;

nexr @Entity公共类产品{

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private long id;

private PetType petType;
private int petNumber;
@ElementCollection
private List<String> goodies;
private String petDescribtion;
private BigDecimal price;

错误：

Caused by: org.hibernate.AnnotationException: mappedBy reference an unknown target entity property: com.knr.domain_ver2.Product.detailsOffer in com.knr.domain_ver2.DetailsOffer.products
    at org.hibernate.cfg.annotations.CollectionBinder.bindStarToManySecondPass(CollectionBinder.java:769) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.cfg.annotations.CollectionBinder$1.secondPass(CollectionBinder.java:719) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.cfg.CollectionSecondPass.doSecondPass(CollectionSecondPass.java:54) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processSecondPasses(InFlightMetadataCollectorImpl.java:1655) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processSecondPasses(InFlightMetadataCollectorImpl.java:1623) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:278) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:847) ~[hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:874) ~[hibernate-entitymanager-5.0.12.Final.jar:5.0.12.Final]
    at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60) ~[spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:360) ~[spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:382) ~[spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:371) ~[spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:336) ~[spring-orm-4.3.14.RELEASE.jar:4.3.14.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624) ~[spring-beans-4.3.14.RELEASE.jar:4.3.14.RELEASE]
    ... 16 common frames omitted

Answer 1

在类Product中，您需要声明字段detailsOffer，并使用引用DetailsOffer的列名将其映射为@ManyToOne和@JoinColumn。

例如：

@ManyToOne
@JoinColumn(name = 'id_details_offer')
private DetailsOffer detailsOffer;

希望它能帮到你。