[英]JPA @ManyToMany with only part of primary Key
I have a many to many relationship betweeen two tables via a third table: 我通过第三个表在两个表之间有很多关系:
TABLE_A A_TO_B TABLE_B
--------- ------------- ------------
KEY (PK) KEY_A (PK, FK) KEY (PK)
--some more Atributes KEY_B (PK, FK) START_DATE (PK)
--some Attributes END_DATE
--some Attributes
As you can see the problem with this Table structure is that Table B
has a composed primary key that contains the startDate of the entry. 如您所见,此表结构存在的问题是Table B
具有包含条目的startDate的组合主键。 This is to be able to have entry versions. 这将能够具有入门版本。 I am not able to change the table structure. 我无法更改表结构。 I want to join TABLE_A
and TABLE_B
in JPA via a @ManyToMany
attribute. 我想通过@ManyToMany
属性在JPA中加入TABLE_A
和TABLE_B
。 But JPA demands, that A_TO_B
knows the full primary key of TABLE_B
. 但是JPA的要求,即A_TO_B
知道的全部主键TABLE_B
。 But I would be fully satisfied to ignore the START_DATE
and just get all entries of TABLE_B
with KEY_B
for a specific KEY_A
. 不过,我会非常满意忽略START_DATE
和刚刚获得的所有条目TABLE_B
与KEY_B
特定KEY_A
。
This is the error: 这是错误:
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [spring_hibernate_configuration.xml]: Invocation of init method failed; nested exception is org.hibernate.AnnotationException: referencedColumnNames(KEY_B) of de.mycompany.entity.model.TableA.listOfBs referencing de.mycompany.entity.model.TableB not mapped to a single property
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1628)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1078)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:857)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543)
at org.springframework.context.annotation.AnnotationConfigApplicationContext.<init>(AnnotationConfigApplicationContext.java:84)
at de.mycompany.Start.main(Start.java:14)
Caused by: org.hibernate.AnnotationException: referencedColumnNames(KEY_B) of de.mycompany.entity.model.TableA.listOfBs referencing de.mycompany.entity.model.TableB not mapped to a single property
at org.hibernate.cfg.BinderHelper.createSyntheticPropertyReference(BinderHelper.java:320)
at org.hibernate.cfg.annotations.CollectionBinder.bindManytoManyInverseFk(CollectionBinder.java:1680)
at org.hibernate.cfg.annotations.CollectionBinder.bindManyToManySecondPass(CollectionBinder.java:1560)
at org.hibernate.cfg.annotations.CollectionBinder.bindStarToManySecondPass(CollectionBinder.java:800)
at org.hibernate.cfg.annotations.CollectionBinder$1.secondPass(CollectionBinder.java:725)
at org.hibernate.cfg.CollectionSecondPass.doSecondPass(CollectionSecondPass.java:54)
at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processSecondPasses(InFlightMetadataCollectorImpl.java:1621)
at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processSecondPasses(InFlightMetadataCollectorImpl.java:1589)
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:278)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:858)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:885)
at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:60)
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:353)
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:370)
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:359)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624)
... 11 more
This is my code: 这是我的代码:
@Entity
@Table(name = "TABLE_A")
public class TableA {
@Id
@Column(name = "KEY", nullable = false)
private int key;
@ManyToMany(fetch = FetchType.EAGER)
@JoinTable(
name = "A_TO_B",
joinColumns = @JoinColumn(name = "KEY_A",
referencedColumnName = "KEY"),
inverseJoinColumns = @JoinColumn(name = "KEY_B",
referencedColumnName = "KEY"))
private List<TableB> listOfBs;
/* More Fields, Getters and setters*/
}
@Entity
@Table(name = "TABLE_B")
public class TableB {
@EmbeddedId
private TableBId id;
@Column(name = "END_DATE", nullable = false)
private LocalDate endDate;
@ManyToMany(mappedBy = "listOfBs")
private List<TableA> listOfAs;
/* More fields, Getters and Setters*/
}
public class TableBId implements Serializable {
@Column(name = "KEY", nullable = false)
private int key;
@Column(name = "START_DATE", nullable = false)
private LocalDate startDate;
/* Getters and Setters*/
}
@Entity
@Table(name = "A_TO_B")
public class AtoB {
@EmbeddedId
private AtoBId id;
/* Getters and Setters*/
}
public class AtoBId implements Serializable {
@Column(name = "KEY_A", nullable = false)
private int keyA;
@Column(name = "KEY_B", nullable = false)
private int keyB;
/* Getters and Setters */
}
When I define the @ManyToMany
with another fake join column containing a date the application starts just fine. 当我用另一个包含日期的伪连接列定义@ManyToMany
,应用程序启动就很好了。
@ManyToMany(fetch = FetchType.EAGER)
@JoinTable(
name = "A_TO_B",
joinColumns = @JoinColumn(name = "KEY_A",
referencedColumnName = "KEY"),
inverseJoinColumns = {@JoinColumn(name = "KEY_B",
referencedColumnName = "KEY"),
@JoinCokumn(name = "SOME_DATE",
referencedColumnName = "START_DATE")})
private List<TableB> listOfBs;
But this wont give me the result I want. 但这不会给我我想要的结果。 I just want to join A_TO_B
and TABLE_B
over KEY_B
. 我只是想加入A_TO_B
和TABLE_B
超过KEY_B
。
For anyone with a similar problem here is what I did in the end: 对于任何有类似问题的人,这都是我最后要做的事情:
I made the list of Bs in A transient, which means that it is not saved in the DB. 我在A瞬态中列出了B的列表,这意味着它没有保存在DB中。 Then I fill it lazyly via the getter: 然后我通过吸气剂将其懒散地填充:
@Entity
@Configurable
@Table(name = "TABLE_A")
public class TableA {
@Id
@Column(name = "KEY", nullable = false)
private int key;
@Transient
private List<TableB> listOfBs;
@Transient
@Autowired
AtoBRepository aToBRepository;
@Transient
@Autowired
TableBRepository tableBRepository;
public List<TableB> getListOfBs(){
if (listOfBs == null){
listOfBs = new ArrayList<>();
List<AtoB> AtoBs = aToBRepository.findByIdKeyA(key);
for (AtoB aToB : AtoBs){
listOfBs.addAll(tableBRepository.findByIdKey(aToB.getKeyB));
}
}
return listOfBs;
}
/* More Fields, Getters and setters*/
}
To autowire the repository in the entity I you load time weaving as described in this thread: load Time weaving with @configurable 要自动连接实体中的存储库,请按照此线程中的说明加载时间编织:使用@configurable加载时间编织
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