休眠：使用外键从关联表中删除记录

Question

I'm new in hibernate. So, I don't know how to do this:

I have 3 tables:

Table Person:

@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 ...
}

Table Event:

@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 ...
}

Table Person-Event:

@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 perfectly (adding new records, creating new objects) except the case, when I try to delete associated records from Event table or Person table:

...
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);
...

After that I get error:

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

How to configure Hibernate with annotations or some other way to get rid of this error?

Answer 1

If you have a complex graph of persistent entities, I think you need to give up using orphanRemoval and remove your entities manually using em.remove() .

orphanRemoval is designed for simple parent-child relationships, where child doesn't make sense without parent. If in your case child may have ohter relationships, perhaps it's not a good case for orphanRemoval .

Answer 2

删除orphanRemoval = true再试一次