为什么我的光标为空?

我正在尝试使用MyBatis的光标。

映射器XML

<select id="selectCursor51" resultMap="someResultMap" resultOrdered="true">
    SELECT
        ...
    FROM
        ...
    <where>
        ...
    </where>
    ORDER BY
        ..., <!-- is this part can be wrong? -->
        some_id ASC
</select>

映射器接口,

@Mapper
public interface SomeMapper {
    List<Some> selectCursor51(...);
}

春季服务,

@Service
public class SomeService {

    @Transactional
    public <R> R some(..., final Function<Cursor<Some>, R> function) {
        ...
        final Cursor<Some> cursor = someMapper.selectCursor51(...);
        return function.apply(cursor);
    }

    @Autowired
    private SomeMapper someMapper;
}

实际查询生成非空结果。 但光标为空。

我做错了什么?