java - 删除多对一关系中删除父级的子级

Question

父类:

public class Article implements Serializable {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
Long id;

@Email
@NotNull
@Column(name = "email")
String email;

@Column(name = "title")
String title;

@Column(name = "published")
Boolean published;

@OneToMany(mappedBy = "article", cascade = {CascadeType.REMOVE},  orphanRemoval = true)
private Set<Comment> comments = new HashSet<>();

// setters and getters
}

子类:

public class Comment implements Serializable {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
Long id;

@Email
@NotNull
@Column(name = "email")
String email;

@JsonIgnore
@ManyToOne
@JoinColumn(name = "article_id", referencedColumnName = "id")
Article article;

// setters and getters
}

我想要做的是，当删除文章时，例如 id =“1”，它应该自动删除其所有评论......那么如何使用注释来做到这一点？ 换句话说 例如，当在 http://localhost:8080/articles/1 上对 postman 发出删除请求时，其中 1 是要删除的文章 ID ...它也应该删除其所有评论

Answer 1

只需将 Article 中的 OneToMany 关系添加到 Comment 即可:

@OneToMany(mappedBy = "article", orphanRemoval = true)
private Set<Comment> comments = new HashSet<>();

从父级到子级的级联 REMOVE 操作需要父级到子级的关系。

更新:添加了orphanRemoval = true