在 Hibernate 中保存对象时遇到问题

Question

也许是一个微不足道的问题，但我查遍了所有能找到的方法，但找不到解决方案

我试图使用post请求保存一个新的GeologicalClass（不是最好的命名，但这就是任务），但是将其保存到数据库时，依赖字段section_id被写入为null

这是我的代码：

@AllArgsConstructor
@NoArgsConstructor
@Getter
@Setter
@Entity
@Table(name = "sections")
public class Section {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private Long id;

    @Column(name = "name", nullable = false)
    private String name;
    private boolean isDeleted;

    @OneToMany(cascade = CascadeType.PERSIST, mappedBy = "section")
    private List<GeologicalClass> geologicalClasses;
}

@AllArgsConstructor
@NoArgsConstructor
@Getter@Setter
@Entity
@ToString(exclude = "section")
@Table(name = "geological_classes")
public class GeologicalClass {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(columnDefinition = "bigint")
    private Long id;

    private String name;
    private String code;
    private boolean isDeleted;

    @JsonBackReference
    @ManyToOne(fetch = FetchType.EAGER, optional = false)
    @JoinColumn(
            name = "section_id",
            insertable = false,
            nullable = false)
    private Section section;
}

@Service
public class GeologicalClassServiceImpl implements GeologicalClassService {
   @Override
    public GeologicalClass createGeologicalClass(GeologicalClass geologicalClass) {
        return geologicalClassRepository.save(geologicalClass);
    }
}

@RestController
@RequestMapping("/api/geological-classes")
@RequiredArgsConstructor
public class GeologicalClassController {
  @PostMapping
    @ResponseStatus(HttpStatus.CREATED)
    public RestResponse createGeologicalClass(@RequestBody GeologicalClass geologicalClass) {
        GeologicalClass createdGeologicalClass = geologicalClassService.createGeologicalClass(geologicalClass);
        return new RestResponse(createdGeologicalClass);
    }
}

Answer 1

我建议使用序列来生成 ID。以下是如何将其应用于 JPA 中的 @ID 字段的示例：

@Getter
@Setter
@Table(name = "table")
@SequenceGenerator(
        name = "table_id_seq",
        sequenceName = "table_id_seq",
        allocationSize = 1)
public class Table {

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "table_id_seq")
    private Long id; 
}