Question

我有下一个实体。每次我从db加载filmManager时会话数量是错误的。

@Table(name = "FILM_MANAGERS")
@Entity
public class FilmManager { 
    @OneToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
    @JoinColumn(name = "FILM_ID",updatable = false,insertable = false)
    private Film film;

@OneToMany(cascade = CascadeType.REMOVE, fetch = FetchType.EAGER,mappedBy = "filmManager")
private List(FilmSession) sessions;

other fields...
}

@Entity
@Table(name = "FILMS")
public class Film {
    @OneToOne(mappedBy = "film")
    private FilmManager filmManager;
    @OneToOne(mappedBy = "film")
    private Ticket ticket;

other fields...
}

@Table(name = "TICKETS")
@Entity
public class Ticket {
    @ManyToOne
    @JoinColumn(name = "USER_ID", updatable = false, insertable = false)
    @JsonBackReference
    private User user;

@OneToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
@JoinColumn(name = "FILM_ID", updatable = false, insertable = false)
private Film film;
}

@Table(name = "FILM_SESSIONS")
@Entity
public class FilmSession {
@ManyToOne
    @JoinColumn(name = "FILM_MANAGER_ID",insertable = false, updatable = false)
    private FilmManager filmManager;
}

    @GetMapping("/films/{filmId}")
    public String getFilm(ModelMap modelMap, @PathVariable("filmId") String filmId) {
        FilmManager filmManager = filmManagerService.getFilm(Long.parseLong(filmId));
        modelMap.addAttribute("filmManager", filmManager);
        modelMap.addAttribute("screenshots", resourceExtractor.getScreenShots(filmManager));
        modelMap.addAttribute("sessions", filmManager.getSessions().stream().map((e) -> e.getSessionTime()).collect(joining(",")));
        System.out.println("amount of sessions: " + filmManager.getSessions().stream().count());
        return "filmPage";
    }
amount of sessions: 11

最后一个SOUT在屏幕上输出11个会话，你可以看到我只有一个。screen1

我发现，每当我为电影插入新票时，视图页面上的会话数量就会增加。因此，基本会话会与票证相乘，而不是1，它会加载11。这是我的门票表screen2

的屏幕

感谢大家的帮助。

Java Jpa OneToMany关系问题

0 个答案: