jpa查找数据库最新一条消息

主要字段说明：

pid：指导记录主键
user_pid：用户主键
competition_project_pid：用户作品 

Mysql表

Repository

/**
 * 指导记录
 * @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测试

控制台

总结

可以通过findFirst或者findTop来获取