Question

有两个实体：

@Entity
@Inheritance(strategy = InheritanceType.JOINED)
public class Person implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    ...
}

@Entity
public class Man extends Person {
    ...
}

尝试执行以下方法：

@Test
public void clear(EntityManager em) {
    EntityTransaction tx = em.getTransaction();
    tx.begin();
    System.out.println(em
            .createQuery("delete from Man m where m.id > 14582647")
            .executeUpdate());
    tx.commit();
}

获取错误：

[ERROR] ORA-00918: column ambiguously defined

hibernate.show_sql显示sql-queries：

Hibernate: insert into HT_Man select man0_.id as id from Man man0_ inner join Person man0_1_ on man0_.id=man0_1_.id where id=14582647
Hibernate: delete from HT_Man

错误发生在，其中id = 14582647 ，因为必须有 id ，例如 man0_.id 。如何生成正确的sql-query？

Answer 1

在Man类上添加@PrimaryKeyJoinColumn注释：

@Entity
@PrimaryKeyJoinColumn(name = "<pk column name in Man table>")
public class Man extends Person {
    ...
}

另外，你应该在Person中定义一个Discriminator列，在Man中定义@DiscriminatorValue，这样Hibernate就可以找出要加入的表（当你引入一个表的女人表时）。

[错误] ORA-00918：列模糊定义

1 个答案: