休眠：从关联表中删除记录与外键

Question

我是新的休眠。所以，我不知道如何做到这一点：

我有3个表：

表人：

@Entity 
@Table(name = "ASD_PERSON") 
public class AsdPerson implements Serializable { 
    @Id 
    @SequenceGenerator(name="seq_name", sequenceName="gen_id_value", allocationSize = 1) 
    @GeneratedValue(generator="seq_name") 
    @Column(name="F_PERSON_ID", nullable = false) 
    private Long fPersonId; 

    @OneToMany(mappedBy = "AsdPerson", 
       cascade = CascadeType.ALL, 
       orphanRemoval = true) 
    private List<AsdPersonEvent> asdPersonEventList; 

    ... setters and getters ... 
} 

表事件：

@Entity 
@Table(name = "ASD_EVENT") 
public class AsdEvent implements Serializable { 
    @Id 
    @SequenceGenerator(name="seq_name", sequenceName="gen_id_value", allocationSize = 1) 
    @GeneratedValue(generator="seq_name") 
    @Column(name="F_EVENT_ID", nullable = false) 
    private Long fEventId; 

    @OneToMany(mappedBy = "AsdEvent", 
       cascade = CascadeType.ALL, 
       orphanRemoval = true) 
    private List<AsdPersonEvent> asdPersonEventList; 

    ... setters and getters ... 
} 

表与人事件：

@Entity 
@Table(name = "ASD_PERSON_EVENT") 
@IdClass(AsdPersonEventPK.class) 
public class AsdPersonEvent implements Serializable { 
    @Id 
    @GenericGenerator(name = "generator", strategy = "foreign", 
         parameters = @Parameter(name = "property", value = "asdPerson")) 
    @GeneratedValue(generator = "generator") 
    @Column(name="F_PERSON_ID", nullable = false, insertable = false, 
      updatable = false) 
    private Long fPersonId; 

    @Id 
    @GenericGenerator(name = "generator", strategy = "foreign", 
         parameters = @Parameter(name = "property", value = "asdEvent")) 
    @GeneratedValue(generator = "generator") 
    @Column(name="F_EVENT_ID", nullable = false, insertable = false, 
      updatable = false) 
    private Long fEventId; 

    @ManyToOne 
    @JoinColumn(name = "F_PERSON_ID", insertable = false, 
       updatable = false) 
    private AsdPerson asdPerson; 

    @ManyToOne 
    @JoinColumn(name = "F_EVENT_ID", insertable = false, 
       updatable = false) 
    private AsdEvent asdEvent; 

    ... setters and getters ... 
} 

Everything works完美（添加新记录，创建新的对象）的情况下除外，当我尝试删除事件表或Person表相关的记录：

... 
AsdEvent ev = getService().get(115); // get record from Event table by id = 115 (for example) 
ev.getAsdPersonEventList().remove(1); // delete some existing records 
getService().merge(ev); 
... 

之后，我得到的错误：

deleted object would be re-saved by cascade (remove deleted object from associations): [database.AsdPersonEvent#database.AsdPersonEventPK@12908fc]

如何配置Hibernate注释或其他方式来摆脱这个错误？

Answer 1

通过去除orphanRemoval = true

Answer 2

如果你有持久实体的复杂的图形再试一次，我想你需要放弃使用orphanRemoval和使用em.remove()手动删除您的实体。

orphanRemoval是专为简单的父母与子女的关系，其中孩子没有父母没有意义。如果在你的情况下，孩子可能有其他的关系，也许这不是orphanRemoval的好例子。