當 Spring Data JPA 從數據庫返回數據時，我遇到了問題。我在這里再試一次。下面是設置。Spring V 1.5.15.RELEASEPGV 9.5.4查詢語句：CREATE TABLE dmg.gps_user_to_data_set (    group_id int8 NOT NULL,    data_set int4 NOT NULL,    agency_id int8 NOT NULL,    FOREIGN KEY (agency_id) REFERENCES funding_agency(agency_id),    FOREIGN KEY (group_id, data_set) REFERENCES data_set(group_id, data_set))WITH (    OIDS=FALSE) ;回購：public interface GpsUserToDataSetTestRepository extends JpaRepository<GpsUserToDataSetTest, DataSetPK> {    @Query(value = "select group_id,data_set,agency_id from gps_user_to_data_set where group_id=?1 and data_set=?2", nativeQuery = true)    List<GpsUserToDataSetTest> test(Long groupId, Long dataSet);    @Query(value = "select group_id,data_set,agency_id from gps_user_to_data_set where group_id=?1 and data_set=?2", nativeQuery = true)    List<Object> test2(Long groupId, Long dataSet);}實體：@Entity@Data@Table(name = "GPS_USER_TO_DATA_SET")public class GpsUserToDataSetTest implements Serializable {    @EmbeddedId    private DataSetPK primaryKey;    @Column(name = "AGENCY_ID")    private Long agencyId;}測試：System.out.println("ID: "+dataSetPK);System.out.println("YYY : ");gpsUserToDataSetTestRepo.test(dataSetPK.getGroupId(), dataSetPK.getDataSetId()).stream().forEach(e -> {    try {        System.out.println(new ObjectMapper().writeValueAsString(e));    } catch(JsonProcessingException jpe) {    }});System.out.println("ZZZ: ");gpsUserToDataSetTestRepo.test2(dataSetPK.getGroupId(), dataSetPK.getDataSetId()).stream().forEach(e -> {    try {        System.out.println(new ObjectMapper().writeValueAsString(e));    } catch(JsonProcessingException jpe) {    }});所以我運行它并得到兩個不同的結果，我希望當接口 GpsUSerToDataSetTest 時封裝的信息應該與我使用 java.lang.Object 運行相同的查詢時完全相同，但是你可以看到 ids 不一樣，下面是數據庫和標準輸出轉儲中的數據。我什至不知道在這里說什么，這對我來說似乎很奇怪，并且可能是一個錯誤？D B：group_id |data_set |agency_id |---------|---------|----------|1356     |1        |2         |1356     |1        |2         |1356     |1        |19        |