Spring JPA 参数值 [1000] 与预期类型不匹配 [ma.mycom.myapp.domain.Client (n/a)]

Question

我有两个名为 Appointement 和 Client 的实体，我想获得所有 指定客户的任命。当我尝试这样做时，我遇到了以下错误消息。

2022-05-24 13:30:41.685 WARN 23252 --- [ XNIO-3 task-1] .m.m.a.ExceptionHandlerExceptionResolver : Resolved [org.springframework.dao.InvalidDataAccessApiUsageException: Parameter value [1000] did not match expected type [ma.mycom.myapp.domain.Client (n/a)]; nested exception is java.lang.IllegalArgumentException: Parameter value [1000] did not match expected type [ma.mycom.myapp.domain.Client (n/a)]]

这是我的实体：

Client.java

@Entity
@Table(name = "CLIENTS")
@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
public class Client implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "sequenceGenerator")
    @SequenceGenerator(name = "sequenceGenerator")
    @Column(name = "id")
    private Long id;

    //other attributes, getters, setters
    
}

Appointment.java

@Entity
@Table(name = "APPOINTMRNTS")
@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
public class Appointment implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "sequenceGenerator")
    @SequenceGenerator(name = "sequenceGenerator")
    @Column(name = "id")
    private Long id;
    //other attributes

    @ManyToOne
    @JoinColumn(name = "ID_CLIENT")
    private Client client;

   //getters, setters
    
}

控制器，以及我如何调用查询：

List<Appointement> clientAppointements = appointementRepository.findAllByClient(idClient);

这是AppointementRepository.java中使用的查询（我猜这是问题的根源）

@Query(
        name = "SELECT pe.* FROM APPOINTEMENTS pe INNER JOIN CLIENTS e ON pe.ID_CLIENT = e.ID WHERE e.id = ?1",
        nativeQuery = true
    )
List<Appointement> findAllByClient(Long idClient);

Answer 1

您的 Appointment class 没有任何类型的名为“客户端 ID”的字段，它只知道它拥有的 Client 实体。

在您的 JPA 存储库方法中，您只能使用实体的现有字段。

解决此问题的两种最标准方法是：

1- 将 Appointment 字段添加到关系的 Client 端以使其成为双向的（我个人推荐这样做）。您的 Client 实体将如下所示：

@Entity
@Table(name = "CLIENTS")
@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
public class Client implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "sequenceGenerator")
    @SequenceGenerator(name = "sequenceGenerator")
    @Column(name = "id")
    private Long id;

    @OneToMany(mappedBy = "client", fetch = FetchType.LAZY)
    List<Appointment> appointments;

    //other attributes, getters, setters
   
}

然后您可以通过获取 Client 对象，然后访问其 appointments 字段来简单地获取约会。

List<Appointement> clientAppointements = clientRepository.findClientByField(field)
.getAppointments();

或者您甚至可以在存储库方法中获得客户的约会：

// in your appointment repository

@Query(value = "SELECT c.appointments FROM Client c WHERE c.id = :cId")
List<Appointment> getAppointmentsById(Long cId);

2- 如果您不想建立双向关系，您应该在使用 Appointment 存储库方法搜索之前获取 Client 对象。

// in your appointment repository
List<Appointment> findByClient(Client client);

// then you can fetch it anywhere
Client client = clientRepository.findById(cliendId);
List<Appointment> clientAppointments = appointmentRepository.findByClient(client);