我正在使用 Hibernate
将 Entity1 连接到 Entity2,其中 Entity2 具有复合主键。
Entity2
包含 2 列 id
和 type
public class Entity2 {
@EmbeddedId
private Entity2PK id;
}
@Embeddable
public class Entity2PK implements Serializable {
@Column(name = "id")
private String id;
@Column(name = "type")
private String type;
}
Entity1
包含 2 列 id
和 entity_2_id
(外键引用 Entity2
)
public class Entity1 {
@Id
@Column(name = "id", updatable = false, nullable = false)
private String id;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name="entity_2_id")
private Entity2 entity2;
}
因此所有调用都失败。有人有解决办法吗?
错误消息:
org.hibernate.AnnotationException: A Foreign key refering Entity2 from Entity1 has the wrong number of column. should be 4
at org.hibernate.cfg.annotations.TableBinder.bindFk(TableBinder.java:646)
at org.hibernate.cfg.ToOneFkSecondPass.doSecondPass(ToOneFkSecondPass.java:102)
at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processEndOfQueue(InFlightMetadataCollectorImpl.java:1814)
at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processFkSecondPassesInOrder(InFlightMetadataCollectorImpl.java:1758)
at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processSecondPasses(InFlightMetadataCollectorImpl.java:1646)
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:286)
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.build(MetadataBuildingProcess.java:83)
at org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:473)
at org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:84)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:689)
最佳答案
您似乎与该用户有同样的问题:AnnotationException: A Foreign key refering has the wrong number of column. should be 2
Entity1 无法将关系存储在单个列中,因为 Entity2 的 id 有 2 列。您可以使用 JoinColumns
而不是 JoinColumn
来解决此问题。
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumns({
@JoinColumn(name = "entity2_id", insertable = false, updatable = false),
@JoinColumn(name = "entity2_type", insertable = false, updatable = false)
})
private Entity2 entity2;
关于java - 外键映射到 Embeddable 类,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/59820972/