mysql - Spring Boot 中的外键(MySQL、Hibernate、JPA)

Question

我正在尝试使用 Spring Boot 编写一个 RESTful API，但我无法找到一种方法来映射我在数据库中的关系。我有一个用户和一个报告表。每个用户可以有多个报告，单个报告由“FROM USER”和“TO USER”列组成，以指示报告的发送者和收件人。我的用户 ID 是主键，对于 Report 表，我使用 AUTO INCREMENT 生成 REPORT ID 作为主键。这是我的用户模型类 -

@Entity
@Table (name = "user")
@EntityListeners(AuditingEntityListener.class)
public class User {
    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    private String firstName;

    private String lastName;

    private String email;

    private String password;

    @OneToMany(mappedBy = "user",cascade = CascadeType.ALL)
    private List<Report> reportReceivedList;

    @OneToMany(mappedBy = "user", cascade = CascadeType.ALL)
    private List<Report> reportSentList;
    /* Getters and setters ..... */
}

这是我的报表模型类 -

@Entity
@Table (name = "report")
@EntityListeners(AuditingEntityListener.class)
public class Report {
    @Id
    @Column (name = "id")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @ManyToOne()
    @JoinColumn(name = "from_user_id")
    private Long fromUserId;    //THIS SHOULD BE FROM "USER" TABLE

    @ManyToOne()
    @JoinColumn(referencedColumnName = "to_user_id")
    private Long toUserId;    //THIS SHOULD BE FROM "USER" TABLE

    @Temporal(TemporalType.DATE)
    @CreatedDate
    private Date createdAt;

    private String observation;

    private String context;

    //Other variables and getters and setters ..... 
}

谁能告诉我正确定义这种关系的方法。我当前的模型不起作用。此外，我希望在删除用户后立即删除 REPORT 类中的行。谢谢!

Answer 1

我最终通过如下更改我的用户类来修复它 -

@OneToMany(cascade = CascadeType.ALL, targetEntity = Report.class)
@JoinColumn(name = "to_user_id")
private List<Report> reportReceivedList;

@OneToMany(cascade = CascadeType.ALL, targetEntity = Report.class)
@JoinColumn(name = "from_user_id")
private List<Report> reportSentList;

然后将我的 Report 类更改为 -

@Column(name = "from_user_id")
private Long fromUserId;

@Column(name = "to_user_id")
private Long toUserId;