Hibernate尽管有CASCADE.ALL

Question

注释mappedBy理想情况下应始终用于双向关系的Parent侧（Cities类），在这种情况下，它应该在Cities类中指向Child类的成员变量'city'（Theater类）

注释@JoinColumn用于指定用于连接实体关联的映射列，此注释可以在任何类（父或子）中使用，但理想情况下，它应仅在一侧使用（在父类或在在这种情况下，子类不在这两种情况下我在双向关系的子级（Branch类）中使用它，表示Branch类中的外键。

所以当我通过PostMan点击服务来检查我的帖子请求是否正常工作。我看到外键列没有正确更新。我的意思是将值设置为null。如果你们想看一下，我已经给出了数据库的图像。

城市：

@Entity
public class Cities {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column
    Long cityId;
    String cityName;

    @OneToMany(cascade = CascadeType.ALL, mappedBy="city", fetch = FetchType.LAZY)
    List<Threatres> movies = new ArrayList<Threatres>();

    public Cities() {
        super();
    }

    public List<Threatres> getMovies() {
        return movies;
    }

    public void setMovies(List<Threatres> movies) {
        this.movies = movies;
    }

    public Long getCityId() {
        return cityId;
    }

    public void setCityId(Long cityId) {
        this.cityId = cityId;
    }

    public String getCityName() {
        return cityName;
    }

    public void setCityName(String cityName) {
        this.cityName = cityName;
    }

}

Threatre ：

@Entity
public class Threatres {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long threatreId;
    String nameOfThreatres;

    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "cityId")
    private Cities city;

    public Threatres() {
        super();
    }

    public Long getThreatreId() {
        return threatreId;
    }

    public void setThreatreId(Long threatreId) {
        this.threatreId = threatreId;
    }

    public Cities getCity() {
        return city;
    }

    public void setCity(Cities city) {
        this.city = city;
    }

    public Long getThreatres() {
        return threatreId;
    }

    public void setThreatres(Long threatreId) {
        this.threatreId = threatreId;
    }

    public String getNameOfThreatres() {
        return nameOfThreatres;
    }

    public void setNameOfThreatres(String nameOfThreatres) {
        this.nameOfThreatres = nameOfThreatres;
    }

}

MyServiceClass

    @Service
        public class MasterService implements CityService, MoviesService, ThreatresService {

            @Autowired
            CitiesRepository cityRepository;
            @Autowired
            MoviesRepository moviesRepository;
            @Autowired
            ThreatresRepository threatresRepository;

            @Override
            public void saveCities(Cities cities) {
                cityRepository.save(cities);

            }

            @Override
            public void saveMovies(Movies movies) {
                moviesRepository.save(movies);

            }

            @Override
            public void saveThreatres(Threatres threatres) {
                threatresRepository.save(threatres);
            }

            @Override
            public List<Cities> findAllCities() {
                return (List<Cities>) cityRepository.findAll();

            }

            @Override
            public Cities findAllCityById(Long id) {

                return cityRepository.findByCityId(id);
            }

        }

控制器类

   `

@RestController
        public class HomeController {

            @Autowired
            CityService cityService;

            @Autowired
            MoviesService moviesService;

            @Autowired
            ThreatresService threatresService;

            @GetMapping("/")
            public void getLoginPage() {

            }

            public void getAllCitites() {

            }

            @PostMapping(value = "/saveCities")
            public void saveCities(@RequestBody Cities cities) {
                cityService.saveCities(cities);
            }

            @PostMapping(value = "/saveMovies")
            public void saveMovies(@RequestBody Movies movies) {
                moviesService.saveMovies(movies);
            }

            @PostMapping(value = "/saveThreatres")
            public void saveThreatres(@RequestBody Threatres threatres) {
                threatresService.saveThreatres(threatres);

            }
        @GetMapping("/finaAllCities")
        public List<Cities> getAllCites() {

            return cityService.findAllCities();

        }

        @GetMapping("/finaAllCitiesbyId/{id}")
        public Cities getCityById(@PathVariable Long id) {
            return cityService.findAllCityById(id);

        }

    }` 

请参阅下面的图片，查看邮寄申请的PostMan数据。

请求

Database Image: You can see the CityId in the table threatres is getting populated with null