在Spring Data和Hibernate中不受控制地删除

时间：2019-02-20 16:39:23

标签： hibernate spring-boot spring-data-jpa

我不是Hibernate的专家，所以我的问题可能微不足道。

我正在编写活动的预订引擎。 使用引擎，可以进行注册，每个注册都有一定数量的参与者。每个注册可以关联一个或多个付款。

对于每个注册，可以对多个房间进行预订。该预订可以是房间的一部分（例如，要共享四人房间的两个参与者的预订），也可以是整个房间。每个房间可以具有对应于特定房间类型的几种房间布置（例如，四人房，三人房或双人间）。预订房间后，所选的房间类型和房间将通过房间分配进行连接，该房间分配与预订有关。

要在Spring中对此进行编码，我设置了以下模型类：

Registration.java 

@Entity
@Table(name = "registrations")
@Data
public class Registration {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id")
    private Long id;

    // other fields

}

Participant.java 

@Entity
@Table(name = "participants")
@Data
public class Participant {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id")
    private Long id;

    @ManyToOne(targetEntity = Registration.class)
    @JoinColumn(name = "registration_id")
    private Registration registration;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "reservation_id")
    private Reservation reservation;

    // other fields
}

Reservation.java 

@Entity
@Table(name = "reservations")
@Data
public class Reservation {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id")
    private Long id;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "room_assignment_id")
    private RoomAssignment roomAssignment;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "registration_id")
    private Registration registration;


    @OneToMany(fetch = FetchType.LAZY)
    @JoinColumn(name = "reservation_id")
    private List<Participant> participants;

    // other fields

}

RoomAssignment.java 

@Entity
@Table(name = "room_assignments")
@Data
public class RoomAssignment {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id")
    private Long id;


    @OneToOne(fetch = FetchType.LAZY, mappedBy = "assignment", cascade = CascadeType.ALL)
    private Room room;

    @OneToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "room_type_id", nullable = false)
    private RoomType roomType;


    @OneToMany(fetch = FetchType.LAZY)
    @JoinColumn(name = "room_assignment_id")
    private List<Reservation> reservations;

}

Room.java 

@Entity
@Table(name = "rooms")
@Data
public class Room {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id")
    private Long id;

    @Column(name = "room_name")
    private String roomName;

    @OneToMany(fetch = FetchType.LAZY )
    @JoinColumn(name = "room_id")
    private List<RoomArrangement> roomArrangements;

    @OneToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "assignment_id")
    private RoomAssignment assignment;

}

最后是RoomArrangement.java 

@Entity
@Table(name = "room_arrangements")
@Data
public class RoomArrangement {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id")
    private Long id;

    @ManyToOne(targetEntity = RoomType.class)
    @JoinColumn(name = "room_type_id", nullable = false)
    private RoomType roomType;

    @ManyToOne(targetEntity = Room.class)
    @JoinColumn(name = "room_id", nullable = false)
    private Room room;

    @Column(name = "priority")
    private Integer priority;

}

所有模型类都有其对应的Repository类，在这里不再赘述，因为它们仅包含方法名称，您可以从代码中看到它们。

我目前正在编写删除注册的程序。为此，我消除了所有参与者和所有付款，然后针对每个预订，查看它是否是对应房间分配的唯一分配，在这种情况下，我也消除了房间分配，并取消了预订，最后注册。我已经用这种方法编码了这一部分：

@Override
public void deleteRegistration(Registration registration) {
    // Deleting payments
    paymentRepository.deleteAll(paymentRepository.findByRegistration(registration));

    // Deleting participants
    participantRepository.deleteAll(participantRepository.findByRegistration(registration));

    List<Reservation> reservations = reservationRepository.findByRegistration(registration);
    for (Reservation res : reservations) {
        RoomAssignment assignment = roomAssignmentRepository.findByReservationsContains(res);

        if (reservationRepository.findByRoomAssignment(assignment).size() == 1) {
            reservationRepository.delete(res);

            Room room = roomRepository.findByAssignment(assignment);
            room.setAssignment(null);
            roomRepository.save(room);

            roomAssignmentRepository.delete(assignment);
        } else {
            reservationRepository.delete(res);
        }
    }

    registrationRepository.delete(registration);
}

结果是很奇怪的：当执行到达roomAssignmentRepository.delete（assignment）;调用，它会因带有消息

的DataIntegrityViolationException中断 
Column 'room_id' cannot be null

我试图记录休眠的呼叫，其中之一绝对让我感到奇怪。

在这里我用相应的java调用列出它们

paymentRepository.deleteAll（此注册没有任何付款）

select payment0_.id as id1_1_, payment0_.amount as amount2_1_, payment0_.paypal_order_id as paypal_o3_1_, payment0_.registration_id as registra5_1_, payment0_.type as type4_1_ from payments payment0_ where payment0_.registration_id=?

participantRepository.deleteAll 

select participan0_.id as id1_0_, participan0_.birth_date as birth_da2_0_, participan0_.birth_place as birth_pl3_0_, participan0_.email as email4_0_, participan0_.facebook_profile as facebook5_0_, participan0_.first_name as first_na6_0_, participan0_.first_time as first_ti7_0_, participan0_.food_intolerances as food_int8_0_, participan0_.food_preferences as food_pre9_0_, participan0_.gender as gender10_0_, participan0_.last_name as last_na11_0_, participan0_.other_food_notes as other_f12_0_, participan0_.registration_id as registr13_0_, participan0_.reservation_id as reserva14_0_ from participants participan0_ where participan0_.registration_id=?
delete from participants where id=?

reservationRepository.findByRegistration 

select reservatio0_.id as id1_3_, reservatio0_.monday as monday2_3_, reservatio0_.registration_id as registra4_3_, reservatio0_.room_assignment_id as room_ass5_3_, reservatio0_.thursday as thursday3_3_ from reservations reservatio0_ where reservatio0_.registration_id=?

roomAssignmentRepository.findByReservations包含

select roomassign0_.id as id1_5_, roomassign0_.room_type_id as room_typ2_5_ from room_assignments roomassign0_ where ? in (select reservatio1_.id from reservations reservatio1_ where roomassign0_.id=reservatio1_.room_assignment_id)
select room0_.id as id1_7_0_, room0_.assignment_id as assignme3_7_0_, room0_.room_name as room_nam2_7_0_ from rooms room0_ where room0_.assignment_id=?

reservationRepository.delete 

select reservatio0_.id as id1_3_, reservatio0_.monday as monday2_3_, reservatio0_.registration_id as registra4_3_, reservatio0_.room_assignment_id as room_ass5_3_, reservatio0_.thursday as thursday3_3_ from reservations reservatio0_ where reservatio0_.room_assignment_id=?
update participants set reservation_id=null where reservation_id=?
delete from reservations where id=?

roomRepository.findByAssignment 

select room0_.id as id1_7_, room0_.assignment_id as assignme3_7_, room0_.room_name as room_nam2_7_ from rooms room0_ where room0_.assignment_id=?

roomRepository.save 

update rooms set assignment_id=?, room_name=? where id=?

roomAssignmentRepository.delete 

update reservations set room_assignment_id=null where room_assignment_id=?
update room_arrangements set room_id=null where room_id=?

最后一次更新room_arrangements设置room_id = null，其中room_id =？当然是打破非null约束的SQL更新。

经过漫长的准备，问题是：为什么Hibernate正在进行最后一次更新，因为我不以任何方式修改任何room_arrangement？在通话的那一刻，我正在修改RoomAssignment类，该类甚至没有与RoomArrangement连接。

1 个答案:

答案 0 :(得分：0)

可爱。通过写问题，我意识到，就像我们在意大利所说的那样，魔鬼在细节中。

从Internet示例中复制和粘贴内容使我错误地注释了RoomAssignment和Room之间的关系。

@OneToOne(fetch = FetchType.LAZY, mappedBy = "assignment", cascade = CascadeType.ALL)
    private Room room;

该问题当然与CascadeType.ALL有关：当我删除分配时，Hibernate也会尝试删除Room，并且在执行此操作时，它会通过清除外键来清理RoomType。当然导致了错误。

我可以做的一课是：从互联网上复制粘贴时要小心：）

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