Mysql 存储库对象与DTO对象的映射

我有一个作用于Table Ride的Repository类

@RestResource(exported = false)
public interface RideRepository extends CrudRepository<Ride, Long> {

@Query(value = "select p.*,  top5.duration_seconds / 1 as         totalRideDurationInSeconds, top5.max_seconds / 1 as maxRideDurationInSeconds, " +
         "top5.avg_distance as averageDistance , top5.driver_id as driver_id,top5.rider_id as rider_id, top5.start_time as start_time, top5.end_time as end_time, top5.distance as distance " +
                    "from (select r.driver_id as driver_id, r.start_time as start_time, r.end_time as end_time, r.distance as distance, r.rider_id as rider_id, "+
                 "avg(r.distance) as avg_distance, " +
                    "sum(to_seconds(r.end_time) - to_seconds(r.start_time)) as duration_seconds, "+
                 "max(to_seconds(r.end_time) - to_seconds(r.start_time)) as max_seconds "+
                 "from ride r "+
                 "where r.start_time >= '2018-08-08T12:12:12'  and "+
                 "r.end_time <= '2018-08-08T18:12:12' "+
                 "group by r.driver_id "+
                 "order by duration_seconds desc "+
                 "limit 5 "+
                 ") top5 join "+
                 "person p "+
                 "on top5.driver_id = p.id" , nativeQuery = true)

    List<TopDriverDTO> findByMaxDuration();

Ride.java：

@Entity
@Table(name = "ride")
public class Ride implements Serializable{

  private static final long serialVersionUID = 9097639215351514001L;

  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  Long id;

  @NotNull
  @Column(name = "start_time")
  String startTime;

  @NotNull
  @Column(name = "end_time")
  String endTime;

  @Column(name = "distance")
  Long distance;

  @ManyToOne
  @JoinColumn(name = "driver_id", referencedColumnName = "id")
  Person driver;

  @ManyToOne
  @JoinColumn(name = "rider_id", referencedColumnName = "id")
  Person rider;

它也有所有的getter、setter方法

p是人物模型

@Entity
@Table(name = "person")
public class Person implements Serializable{

private static final long serialVersionUID = 7401548380514451401L;

public Person() {}

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
Long id;

@Column(name = "name")
String name;

@NotNull
@Email
@Column(name = "email")
String email;

@Column(name = "registration_number")
String registrationNumber;
}

上面的查询工作正常。 我使用了Ride-in存储库类定义。 如果我在最后一行使用骑乘

List<Ride> findByMaxDuration();

它很好用

但如果我在最后一行用TopDriverDTO

 List<TopDriverDTO> findByMaxDuration();

然后抛出org.springframework.core.convert.ConverterNotFoundException

我们不能映射这个吗？？

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有什么帮助吗？？？

如果我们检查crudepository的实现，它会扩展存储库接口

Spring数据存储库抽象的中心接口是存储库，这可能并不令人惊讶。它接受要管理的域类以及域类的id类型作为类型参数

从您的代码：

public interface RideRepository extends CrudRepository<Ride, Long>...

您正在指定此存储库的域类为Ride，Id类型为Long

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当查询返回结果时，存储库将发现结果的类型与定义的域类不同，并将抛出所述错误。

您可以使用ResultTransformer。你的情况解释得很好。您可以看一看。@ErfanAhmedEmon:它在询问persistence.xml。我没有使用任何持久性xml。所以，没有解决问题。我知道这一点。我已经在我的问题中解释了这一点。解决这个问题的办法是什么？

public interface RideRepository extends CrudRepository<Ride, Long>...