java - JPA:如何创建与实体类型相同的字段？

Question

我的类(class)看起来像

@Entity
public class Version extends MutableEntity {
    @Column(nullable = false)
    private String name;
    @Column(nullable = false)
    @Enumerated(EnumType.STRING)
    private VersionType type;
    @Column(nullable = false)
    @Enumerated(EnumType.STRING)
    private VersionStatus status;
    @Column(nullable = true)
    private DateTime publishedOn;
    @Column(nullable = true)
    private DateTime retiredOn;
    @Column
    private Version parentVersion;

我想要一个与 Version 类型相同的 parentVersion，但我的测试失败

@Test
public void testVersion() {
    Version version = new Version("testVersion", VersionType.MAJOR);
    version = crudService.create(version);
    assertNotNull(version.getId());
}

我看到错误为

Caused by: org.hibernate.MappingException: Could not determine type for: com.myorg.project.versioning.entities.Version, at table: Version, for columns: [org.hibernate.mapping.Column(parentVersion)]

如何解决这个问题？

Answer 1

这不是基本属性。它是关系，因为值(value)是其他实体。因此@ManyToOne应该使用注释:

@ManyToOne
private Version parentVersion;

如果需要双向关系( parent 了解 child )，可以通过添加以下内容来完成:

@OneToMany (mappedBy = "parentVersion")
private List<Version> childVersions;