jpa查找數據庫最新一條消息

主要字段說明：

pid：指導記錄主鍵
user_pid：用戶主鍵
competition_project_pid：用戶作品 

Mysql表

Repository

/**
 * 指導記錄
 * @date 2020/3/24 9:26
 */
@Repository
public interface CompetitionProjectGuideRepository extends JpaRepository<CompetitionProjectGuide, String> {

    Optional<CompetitionProjectGuide> findFirstByCompetitionProjectPidOrderByUpdateAtDesc(Long pid);

}

Service

    public Optional<CompetitionProjectGuide> findFirstByCompetitionProjectPidOrderByUpdateAtDesc(Long pid) {
        return repository.findFirstByCompetitionProjectPidOrderByUpdateAtDesc(pid);
    }

Controller

    @RequestMapping(method = {RequestMethod.GET}, value = "/task/project/guide")
    public ResponseEntity getGuide(Long pid) {
        Optional<CompetitionProjectGuide> guide = competitionProjectGuideService.findFirstByCompetitionProjectPidOrderByUpdateAtDesc(pid);
        guide.orElseThrow(() -> new BusinessException(
                HttpStatus.BAD_REQUEST, Translator.toLocale("guide.NotExists.message")));
        return ResponseEntity.ok(guide);
    }

postman測試

控制檯

總結

可以通過findFirst或者findTop來獲取