Spring Data@OneTomany与@Jointable的关系-如何修复外键约束冲突？

Question

当使用Spring数据@OneTomany关系和@Jointable时，如何修复外键约束冲突？

@Entity
@Data
public class Email {
    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "email_seq")
    @SequenceGenerator(name = "email_seq", sequenceName = "email_seq")
    private Long id;

    @NotNull
    private String title;

    @OneToMany
    @JoinTable(
            name = "email_attachment",
            joinColumns = @JoinColumn(name = "EMAIL_ID"),
            inverseJoinColumns = @JoinColumn(name = "ATTACHMENT_ID")
    )
    private List<Attachment> attachments;

    ...
}

@Entity
@Data
public class Attachment {
    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "attachment_generator")
    @SequenceGenerator(name = "attachment_generator", sequenceName = "attachment_seq")
    private Long id;

    ...
}

当我尝试像这样删除附件时：

attachmentRepository.delete(id)

它会抛出以下错误：

错误：表“Attachment”上的update或delete违反表“Email_Attachment”上的外键约束“Email_Attachment_Attachment_ID_FKEY”详细信息：键(id)=(6)仍然从表“Email_Attachment”中引用。

Answer 1

您还需要使用@ManyToOne在Attachment中创建关系。

Attachment.java

@Entity
@Data
public class Attachment {
    // ...

    @ManyToOne(mappedBy = "attachments")
    private Email email;

    // ...
}