JPA onetoMany/ManytoOne 持续存在 - 违反完整性约束 - 找不到父键

我的映射文件（相关数据）：

Parent:

@Entity
@Table(name = "ATTRIBUTE_NAME", uniqueConstraints = @UniqueConstraint(columnNames = "NAME_TEXT"))
@SequenceGenerator(name="ATTRIBUTE_NAME_SEQ",    sequenceName="ATTRIBUTE_NAME_SEQ", initialValue = 1, allocationSize = 1)
public class AttributeNameVo implements Serializable {

    @Id
    @GeneratedValue(strategy=GenerationType.SEQUENCE,    generator="ATTRIBUTE_NAME_SEQ")
    @Column(name = "ATTRIBUTE_ID", unique = true, nullable = false, precision = 6, scale = 0)
    private int attributeId;

    @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "attributeNameVo")
    private Set<AttributeFunctionalUsageVo> attributeFunctionalUsageVos = new HashSet<AttributeFunctionalUsageVo>(0);

Child:

@Entity
@Table(name = "ATTRIBUTE_FUNCTIONAL_USAGE")
public class AttributeFunctionalUsageVo implements Serializable {

        @EmbeddedId
        @AttributeOverrides({@AttributeOverride(name = "attributeId", column = @Column(name = "ATTRIBUTE_ID", nullable = false, precision = 6, scale = 0) ),
                             @AttributeOverride(name = "functionalAreaCd", column = @Column(name = "FUNCTIONAL_AREA_CD", nullable = false, length = 5) ) })
        private AttributeFunctionalUsageIdVo id;

        @ManyToOne(fetch = FetchType.LAZY)
        @JoinColumn(name = "attributeId", referencedColumnName="ATTRIBUTE_ID", nullable = true, insertable = false, updatable = false)
        private AttributeNameVo attributeNameVo;

然后我用代码（伪代码）来做：

  AttributeNameVo attr = new AttributeNameVo();
  AttributeFunctionalUsageVo attrFunc = new AttributeFunctionalUsageVo();
  attr.getAttributeFunctionalUsageVos().add(attrFunc);
  attrFunc.setAttributeNameVo(attr);

在 DAO 中：

  em().persist(attr);

日志结果显示：

select ATTRIBUTE_NAME_SEQ.nextval from dual

insert into ATTRIBUTE_NAME (ACTIVE_FL, DATE_CREATED, DATE_MODIFIED,  DISPLAY_SEQ_NO, EXTERNAL_REF_ID, HINT_TEXT, LOV_FL, MAX_LENGTH, MAX_RANGE, MIN_RANGE, NAME_TEXT, POS_FL, PUBLIC_FL, RAPID_SEARCH_FL, REQUIRED_FL, TYPE_CD, USER_CREATED, USER_MODIFIED, ATTRIBUTE_ID) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)

insert into ATTRIBUTE_FUNCTIONAL_USAGE (DATE_CHANGED, DATE_CREATED, DATE_MODIFIED, USER_CREATED, USER_MODIFIED, ATTRIBUTE_ID, FUNCTIONAL_AREA_CD) values (?, ?, ?, ?, ?, ?, ?)

然后就报错了：

ORA-02291: integrity constraint (ATTR_FUNCTIONAL_USAGE_ATTRB_FK) violated - parent key not found

希望能帮助解决此问题。我已经尝试了很多事情，但仍然一无所获......

根据评论中的问题，可嵌入 id 的实体映射是：

public class AttributeFunctionalUsageIdVo implements Serializable {

@Column(name = "ATTRIBUTE_ID", nullable = false, precision = 6, scale = 0)
private int attributeId;

您的解决方案是必需的，因为您已将 AttributeFunctionalUsageVo 中的 attributeNameVo 映射设置为只读（insertable = false，updatable = false），因此 JPA 需要检查可嵌入 ID 中“attributeId”字段的其他映射以设置其值。如果您不使用值手动更新该字段，则插入发生时该字段将为空，这就是失败的原因。

根据您使用的 JPA 版本，有许多选项。如果必须使用 JPA 1.0，则可以修改映射，使 attributeNameVo 可写，而 embeddable 中的映射为只读（切换两个映射上的可插入、可更新设置）。然后，JPA 将从关系中提取“attributeId”字段，忽略对嵌入 ID 字段的任何更改。这将导致它为空，除非您刷新或以其他方式从数据库重新加载实体。

JPA 2.0引入了其他选项，例如允许将关系标记为ID，甚至声明连接字段映射到 ID https://docs.oracle.com/javaee/6/api/javax/persistence/MapsId.html场地。然后您将使用：

@ManyToOne(fetch = FetchType.LAZY)
@MapsId("attributeId")
private AttributeNameVo attributeNameVo;

其中“attributeId”是嵌入式 ID 内映射的名称。然后，JPA 将使用 AttributeNameVo 的主键为您设置嵌入 ID 中的 attributeId 值，并正确处理插入。