在bidrectional自引用表中删除导致JPA

Question

我正在将JPA与Spring Boot结合使用（如果重要）并创建了两个表FileSystem和Media。两者都通过InheritanceType.JOINED关系连接（请参阅ER图）。此外，Filesystem是一个自引用表，它存储文件/文件夹的“树”及其子项和父项。

代码如下：

FileSystem.java

@Entity
@Inheritance(strategy=InheritanceType.JOINED)
public class FileSystem {

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

 private String name;

 public enum Type { FOLDER, FILE}

 @ManyToOne
 @JoinColumn(name="parent")
 @JsonBackReference
 private FileSystem parent;

 @OneToMany(mappedBy = "parent", cascade = CascadeType.ALL,orphanRemoval = true)
 @JsonManagedReference
 List<FileSystem> childs = new ArrayList<FileSystem>();

 FileSystem.Type type;
 }

Media.java

@Entity
public class Media extends FileSystem implements FieldHandled{
@JsonIgnore
private FieldHandler fieldHandler;

@JsonIgnore
  @Lob
  @Column( length = 100000 )
  @Basic(fetch = FetchType.LAZY, optional = false)
 private byte[] data;
 }

MediaRepository.java

public interface MediaRepository extends JpaRepository<Media, Long>{
Media save(Media pageTemplate);

Media findOne(Long id);

public List<Media> findAllByParentId(Long parent);
public List<Media> findAllByParentIsNull();
public List<Media> findByName(String name);
}

在我的控制器方法中删除

...
MediaRepository mediaRepository;
mediaRepository.delete(mediaToDelete);
...

添加新媒体，获取它们等等到目前为止工作正常。但是，当我使用我的扩展delete()为FileSystem调用具有多个子（和子项）的JpaRepository时，我得到以下异常：

  

无法删除或更新父行：外键约束失败（repo。file_system，CONSTRAINT FKf57w77uiwcpfmbtl9lpuq9j9m FOREIGN KEY（parent）参考file_system （id））

最奇怪的是日志。似乎在第一步中JPA正在删除媒体行（由于InheritanceType是JOINED，IMO是正确的），然后尝试删除文件系统行（IMO不正确，因为它应该首先以递归方式删除它的所有子节点）：

2016-10-19 16:21:43.530 TRACE 11412 --- [nio-8080-exec-1] org.hibernate.type.EnumType              : Returning [FOLDER] as column [type3_6_0_]
2016-10-19 16:21:43.530 DEBUG 11412 --- [nio-8080-exec-1] org.hibernate.SQL                        : delete from media where id=?
Hibernate: delete from media where id=?
2016-10-19 16:21:43.531 TRACE 11412 --- [nio-8080-exec-1] o.h.type.descriptor.sql.BasicBinder      : binding parameter [1] as [BIGINT] - [65]
2016-10-19 16:21:43.533 DEBUG 11412 --- [nio-8080-exec-1] org.hibernate.SQL                        : delete from file_system where id=?
Hibernate: delete from file_system where id=?
2016-10-19 16:21:43.534 TRACE 11412 --- [nio-8080-exec-1] o.h.type.descriptor.sql.BasicBinder      : binding parameter [1] as [BIGINT] - [65]
2016-10-19 16:21:43.535  WARN 11412 --- [nio-8080-exec-1] o.h.engine.jdbc.spi.SqlExceptionHelper   : SQL Error: 1451, SQLState: 23000
2016-10-19 16:21:43.535 ERROR 11412 --- [nio-8080-exec-1] o.h.engine.jdbc.spi.SqlExceptionHelper   : Cannot delete or update a parent row: a foreign key constraint fails