Question

我有一个令人困惑的问题，我还没弄清楚如何解决。如果你能提出我如何解决问题的建议，我将不胜感激。

所以我有以下实体关系模型here。

User.class的映射是：

@Entity
@Table(name = "CRM_USER")
public class User {    

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "USER_ID")
    private Long id;

    @Column(name = "FIRST_NAME")
    private String firstName;

    @Column(name = "LAST_NAME")
    private String lastName;

    @Column(name = "BIRTHDATE")
    private Date birthDate;

    @Column(name = "EMAIL")
    private String email;

    @OneToOne(cascade = CascadeType.ALL)
    @PrimaryKeyJoinColumn
    private UserAdditionalInfo additionalInfo;

    @ManyToOne
    @JoinColumn(name = "TEAM_FK")
    private Team team;

    @ManyToOne
    @JoinColumn(name = "JOB_FK")
    private Job job;

    @ManyToOne
    @JoinColumn(name = "ORGANIZATION_FK", nullable = false)
    private Organization organization;

    @OneToOne(cascade = CascadeType.ALL)
    @PrimaryKeyJoinColumn
    private Security security;

    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "INFO_FILE_FK")
    private InfoFile profilePicture;

    @ManyToOne
    @JoinColumn(name = "COUNTRY_FK")
    private Country country;

   // Getters and Setters
}

Comment.class的映射是：

@Entity
@Table(name = "CRM_COMMENT")
public class Comment implements Serializable {

    private static final long serialVersionUID = -104145851368148154L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "COMMENT_ID")
    private Long id;

    @ManyToOne
    @JoinColumn(name = "ARTICLE_ID")
    private Article article;

    @ManyToOne
    @JoinColumn(name = "USER_FK", nullable = false)
    private User createdUser;

    @Column(nullable = false)
    private String comment;

    @Column(name = "CREATION_DATE", nullable = false)
    private Date creationDate;

    @Column(name = "MODIFICATION_DATE")
    private Date modificationDate;

    @OneToMany(cascade = {CascadeType.ALL}, orphanRemoval = true)
    @JoinTable(name = "CRM_COMMENT_LIKE",
            joinColumns = {@JoinColumn(name = "COMMENT_ID")},
            inverseJoinColumns = {@JoinColumn(name = "USER_ID")})
    private Set<User> fans = new LinkedHashSet<>();

    // Getters and Setters
}

Article.class的映射是：

@Entity
@Table(name = "CRM_ARTICLE")
public class Article implements Serializable {

    // other properties

    @OneToMany(mappedBy = "article", cascade = {CascadeType.ALL}, orphanRemoval = true)
    @OrderBy("id DESC")
    private Set<Comment> comments = new LinkedHashSet<>();

    // Getters and Setters
}

问题与Comment和User - CRM_COMMENT_LIKE之间的ManyToMany关系有关。
实际上，当我在评论中添加一些新的'粉丝'时，没有问题。

@Override
    public boolean giveAnLikeToComment(Long commentId, User fan) {
        Comment comment = commentDao.get(commentId);
        if (Objects.isNull(comment)|| BooleanUtils.isTrue(comment.getFans().contains(fan))) {
            return false;
        }

        comment.getFans().add(fan);
        commentDao.update(comment);

        return true;
    }

当我尝试删除一些评论时会出现问题，评论中至少有一个'喜欢'/'粉丝'。

@Override
    public boolean deleteCommentById(final Long commentId) {
        Comment comment = commentDao.get(commentId);
        if (Objects.nonNull(comment)) {
            Article article = comment.getArticle();
            article.getComments().remove(comment);
            comment.setFans(null); // This line fix the problem
            articleDao.update(article);
            return true;
        }
        return false;
    }

所以在这种情况下，我管理文章（评论的父母）和评论本身之间的关系。这很容易，因为它们之间的连接是双向的。但那些粉丝呢？我无法删除Comment和CRM_COMMENT_LIKE关系之间的连接，因为用户不知道CRM_COMMENT_LIKE或评论。我想删除评论，删除CRM_COMMENT_LIKE中创建的所有关系。但是我阻止了，因为Hibernate会抛出一个异常，上面写着：

删除的对象将通过级联重新保存（从关联中删除已删除的对象）： [crm.alltogether.core.admin.model.User＃1];嵌套异常是 org.hibernate.ObjectDeletedException：将重新保存已删除的对象通过级联（从关联中删除已删除的对象）： [crm.alltogether.core.admin.model.User＃1]

这是我的问题，所以如果您有任何建议，我会很高兴看到它：）

最诚挚的问候，

Answer 1

orphanRemoval=true和Article之间需要Comment级联。然后你会这样做。

if (Objects.nonNull(comment)) {
      Article a = comment.getArticle();
      a.getComments().remove(comment);
      articleDao.saveOrUpdate(a);
      return true;
}

这会照顾删除孤立评论，因为你已经在fans上有一个级联，它也会删除该关联。我建议您在orphanRemoval=true上使用级联fans。

删除@ManyToMany关联时出现Hibernate异常

1 个答案: