Hibernate ManyToMany delete/remove实体无法删除或更新父行：外键约束失败

Question

我在两个实体之间有很多关系。

作者-

代码如下：

@Entity
public class Author

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "author_id")
private Long author_id;

@ManyToMany(cascade = CascadeType.ALL)
@JoinTable(name = "Author_Books", joinColumns = @JoinColumn(name = "author_id"), inverseJoinColumns = @JoinColumn(name = "book_id"))
private List<Books> books;


@Entity
@Table(name = "Books")
public class Books

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "book_id")
private Long book_id;

@ManyToMany(mappedBy = "books")
@NotNull
private List<Author> authors;

现在，当我尝试执行以下操作时，我得到以下错误：

书刀。删除（书籍）；\n错误：无法删除或更新父行：外键约束失败（lucytestauthor\u books，约束FK\u d7blldnja6fa73ktxehccduq外键（book\u id）引用book（book\u id）

我搜索了整个网络，堆栈溢出，但似乎找不到答案。任何人如有此问题，也将不胜感激。

Answer 1

我删除了MySQL中的所有表，这次让hibernate用以下代码从头开始创建它们，从而实现了这一点：

@ManyToMany(cascade = CascadeType.ALL)
    @JoinTable(name = "Author_Books", joinColumns = @JoinColumn(name = "author_id"), inverseJoinColumns = @JoinColumn(name = "book_id"))
    @Valid
    private List<Books> books;

@ManyToMany(cascade = {CascadeType.MERGE, CascadeType.PERSIST, CascadeType.REFRESH, CascadeType.DETACH})
    @JoinTable(name = "Author_Books", joinColumns = @JoinColumn(name = "book_id"), inverseJoinColumns = @JoinColumn(name = "author_id"))
    @Valid
    private List<Author> authors;

我希望这能让每个人都免受它给我带来的头痛。