测试中的 Hibernate OnDelete 级联不起作用

Question

我有单向相关实体:

@Entity
public class Book {
    private String isbn;
}

@Entity
private class Recommentation {
    @ManyToOne(optional = false, fetch = FetchType.LAZY)
    @JoinColumn(name = "book_id", nullable = false)
    @OnDelete(action = OnDeleteAction.CASCADE)
    private Book book;
}

以及以下测试:

@RunWith(SpringRunner.class)
@DataJpaTest
public class BookRepositoryTest {

    @Autowired
    private TestEntityManager testEntityManager;

    @Autowired
    private BookRepository bookRepository;

    @Test
    public void delete() {
        // given
        String isbn = "isbn-1";
        Book book = new Book();
        book.setIsbn(isbn);
        testEntityManager.persist(book);


        Recommendation recommendation = new Recommendation();
        recommendation.setBook(book);
        testEntityManager.persist(recommendation);

        // when
        bookRepository.deleteBookByIsbn(book.getIsbn());

        // then
        assertThat(testEntityManager.find(Book.class, book.getId())).isNull();
        assertThat(testEntityManager.find(Recommendation.class, recommendation.getId())).isNull();
    }

}

@OnDelete(action = OnDeleteAction.CASCADE) 当此代码不是从测试中调用但在测试中我得到异常，建议未被书删除。

我还尝试从为 hibernate 查询记录的 sql 中获取任何信息，但我看不到此测试的任何 delete 语句。

我不想对实体使用双向链接，只是想了解如何解决这个具体问题或以某种方式调试它。

Answer 1

@ManyToOne#cascade

@ManyToOne(optional = false, cascade = CascadeType.ALL)
@JoinColumn(name = "book_id", nullable = false)
private Book book;

编辑 1:

@ManyToOne(optional = false)
@JoinColumn(name = "book_id",
        nullable = false,
        foreignKey = @ForeignKey(
                foreignKeyDefinition = "FOREIGN KEY (book_id) REFERENCES book(id) ON DELETE CASCADE"
        )
)
private Book book;

如果您不想要双向映射并且您的模式是从您的实体创建的，则以下方法应该可以解决问题。

如果您从 SQL 创建模式，您也可以在脚本中创建这样的外键。

这种方法也期望只执行一个删除查询。