Spring Data Jpa实现自定义repository转DTO

近期项目中需要 关联 几张表再把字段转出来，在这里记录以下，我感觉网上写的都不太规范和清晰。

@Entity
@SqlResultSetMapping(
    name="TestMapping",
    entities = {
        @EntityResult(
            entityClass = com.xxx.xx.data.model.TestEntity.class,
            fields = {
                @FieldResult(name="id",column="id"),
                @FieldResult(name="localTime",column="time"),
                @FieldResult(name="maximumAppointment",column="maxAppointment"),
            }
        )
    }
)
@NamedNativeQuery(name="getTestQuery",
    query="select tableC.id as id,tableB.time,tableC.maximumAppointment as maxAppointment from tableB " +
        "               inner join tableA on tableA.id = tableB.tableAId " +
        "               inner join tableC on tableB.id = tableC.tableBId " +
        "               inner join custom on custom.id = tableA.customId " +
        "where " +
        "  tableA.locationId = :locationId" +
        "  and custom.id = :customId" +
        "  and tableB.deleted = false ", resultSetMapping="TestMapping")
@Data
public class TestEntity {
  @Id
  private String id;
  private LocalTime localTime;
  private Integer maximumAppointment;
}

需要声明接口：

@Repository
public interface TestEntityRepository extends JpaRepository<TestEntity,String> {

  @Query(name="getTestQuery")
  List<TestEntity> getTestQuery(String locationId, String customId);

}

若不想声明接口，那可以用EntityManager 来实现。

CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持小牛知识库。