Question

我已经映射了两个类之间的双向关系。情况就是这样：我有旅行和用户。用户应该能够订阅旅行并取消订阅。所以我不想删除对象，只删除连接表中的行。目前，订阅部分有效，但不能取消订阅。

当我测试它时，更改是在内存中进行的，而不是在数据库中进行的。可能有什么不对？我的代码如下所示。

跳闸：

@ManyToMany(mappedBy = "enrolledExecutionMoments", cascade = {
        CascadeType.ALL, CascadeType.ALL }, fetch = FetchType.EAGER)
private List<User> tripExecutionMomentParticipators = new ArrayList<User>();

public TripExecutionMoment() {

}

public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

@JsonIgnore
public List<User> getTripExecutionMomentParticipators() {
    return tripExecutionMomentParticipators;
}

public void setTripExecutionMomentParticipators(
        List<User> tripExecutionMomentParticipators) {
    this.tripExecutionMomentParticipators = tripExecutionMomentParticipators;
}

public void addEnrollement(User user) {
    tripExecutionMomentParticipators.add(user);
}

public void removeEnrollement(User user) {
    tripExecutionMomentParticipators.remove(user);
}

用户：

@Entity
@Table(name = "t_user")
public class User {

    @Id
    @GeneratedValue
    private int id;

    @NotBlank(message = "err_invalid_mail")
    @Email(message = "err_invalid_mail")
    private String email;

    @ManyToMany(cascade = { CascadeType.ALL, CascadeType.ALL }, fetch = FetchType.EAGER)
    @JoinTable(joinColumns = { @JoinColumn(name = "userId") }, inverseJoinColumns = { @JoinColumn(name = "tripExecutionMomentId") })
    private List<TripExecutionMoment> enrolledExecutionMoments = new ArrayList<TripExecutionMoment>();

    public User() {
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public int getId() {
        return id;
    }

    @JsonIgnore
    public TripExecutionMoment getCheckedInTripExecutionMoment() {
        return checkedInTripExecutionMoment;
    }

    public void setCheckedInTripExecutionMoment(
            TripExecutionMoment checkedInTripExecutionMoment) {
        this.checkedInTripExecutionMoment = checkedInTripExecutionMoment;
    }

    public void addEnrollement(TripExecutionMoment tripExecutionMoment) {
        enrolledExecutionMoments.add(tripExecutionMoment);
    }

    public void removeEnrollement(TripExecutionMoment tripExecutionMoment) {
        enrolledExecutionMoments.remove(tripExecutionMoment);
    }
}

这是我注册（订阅）和取消注册（取消订阅）

的代码

@Transactional
public void enrollParticipator(User user,
        TripExecutionMoment tripExecutionMoment)
        throws AlreadyBoundException {
    if (tripExecutionMoment.getTripExecutionMomentParticipators().contains(
            user)) {
        throw new AlreadyBoundException(
                "This user is already enrolled for this trip");
    }
    tripExecutionMoment.addEnrollement(user);
    user.addEnrollement(tripExecutionMoment);

    getEntityManager().merge(tripExecutionMoment);
}

@Transactional
public void disenrollParticipator(User user,
        TripExecutionMoment tripExecutionMoment) {
    tripExecutionMoment.removeEnrollement(user);
    user.removeEnrollement(tripExecutionMoment);
    getEntityManager().merge(user);
}

无法从连接表中删除行（多对多）

0 个答案: