休眠：從關聯表中刪除記錄與外鍵

Question

我是新的休眠。所以，我不知道如何做到這一點：

我有3個表：

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 ... 
} 

表與人事件：

@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（添加新記錄，創建新的對象）的情況下除外，當我嘗試刪除事件表或Person表相關的記錄：

... 
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); 
... 

之後，我得到的錯誤：

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

如何配置Hibernate註釋或其他方式來擺脫這個錯誤？

Answer 1

通過去除orphanRemoval = true

Answer 2

如果你有持久實體的複雜的圖形再試一次，我想你需要放棄使用orphanRemoval和使用em.remove()手動刪除您的實體。

orphanRemoval是專爲簡單的父母與子女的關係，其中孩子沒有父母沒有意義。如果在你的情況下，孩子可能有其他的關係，也許這不是orphanRemoval的好例子。