Spring Data JPA 不保存一对多映射

Question

我有 Worker 和 Department 实体。 Department 包含 Worker 的列表，Worker 包含 Department 实体。所以这是一对多的关系。

工人

    @Getter
    @Setter
    @AllArgsConstructor
    @NoArgsConstructor
    @Entity
    public class Worker {
    
        @Id
        @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "worker_sequence")
        @SequenceGenerator(name = "worker_sequence", sequenceName = "worker_sequence", allocationSize = 1)
        private Long workerId;
        private String name;
        private String lastName;
        private String email;
        private LocalDate birth;
    
        @ManyToOne()
        @JoinColumn(name = "department_id")
        private Department department;
    
    }

部门

@Entity
@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
public class Department {


    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "department_sequence")
    @SequenceGenerator(name = "department_sequence", sequenceName = "department_sequence", allocationSize = 1)
    private Long departmentId;
    private String name;

    @OneToMany(mappedBy = "department", cascade = CascadeType.ALL)
    private List<Worker> workers = new ArrayList<>();

    public void addWorker(Worker worker) {
        workers.add(worker);
    }
}

控制器

@RestController
@RequestMapping("api")
public class DepartmentWorkerController {

    DepartmentService departmentService;
    WorkerService workerService;

    @Autowired
    public DepartmentWorkerController(DepartmentService departmentService, WorkerService workerService) {
        this.departmentService = departmentService;
        this.workerService = workerService;
    }

    @PutMapping("department/{departmentId}/worker/{workerId}")
    public Department assignWorkerToDepartment(@PathVariable("departmentId") Long departmentId, @PathVariable("workerId") Long workerId) {
        Department department = departmentService.getDepartmentById(departmentId);
        Worker worker = workerService.getWorkerByID(workerId);
        department.addWorker(worker);
        return departmentService.saveDepartment(department);
    }
}

问题是没有错误但是关联没有保存。调试时，一切似乎都很好。

Answer 1

查看双向关系在 hibernate.When 中的工作原理您声明了 List 并将关系映射到 Department 不创建另一个 table 并在 worker table 中使用也创建了 department_id =] 作为 relationship.When 的目标，您将 Worker 添加到部门列表 class 在那种情况下，您的 Worker 部门为空，正如您所说的休眠以在您的 Worker 中使用 department_id table 作为关系所有者 hibernate没有意识到这个关系。要解决您的问题，您需要将部门设置为工作人员 worker.setDepartment(department) 然后将该工作人员添加到部门列表并保存该部门，然后该工作人员将通过级联和 department_id 将设置为您需要单独保存它们

Spring Data JPA 不保存一对多映射

Spring Data JPA not saving one-to-many mapping

java

hibernate

spring-data-jpa

spring-boot