近期專案中需要 關聯 幾張表再把欄位轉出來，在這裡記錄以下，我感覺網上寫的都不太規範和清晰。

@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;
}

需要宣告介面：

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

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

}

若不想宣告介面，那可以用EntityManager 來實現。

CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支援我們。