不要在循环中操作数据库(案例)

各位在写代码的时候千万不要在循环中对数据库进行操作,这样会大大降低数据库的性能,今天在写接口的时候碰到了这种情况,被组长说了一下,于是改了改,代码奉上:

    @Overridepublic List<ScrInspectionVo> selectByMcId(String id) {List<ScrInspectionVo> inspectionVos = this.list(new LambdaQueryWrapper<ScrInspection>().eq(ScrInspection::getMcId,id).orderByDesc(ScrInspection::getSort)).stream().map(scrInspection -> {ScrInspectionVo scrInspectionVo = new ScrInspectionVo();scrInspectionVo.setId(scrInspection.getId());scrInspectionVo.setMcId(scrInspection.getMcId());scrInspectionVo.setItemId(scrInspection.getItemId());scrInspectionVo.setStatus(scrInspection.getStatus());scrInspectionVo.setCreateTime(scrInspection.getCreateTime());scrInspectionVo.setSort(scrInspection.getSort());scrInspectionVo.setType(scrInspection.getType());scrInspectionVo.setCreateBy(scrInspection.getCreateBy());//项目筛查数据处理if (scrInspection.getType().equals(ScreeningConst.PROJECT_SCREENING)){//根据检查项目id查询检查项目名称CheckItemTreeVO checkItemTreeVO = remoteKnowledgeApi.selectOne(scrInspection.getItemId(), SecurityConstants.FROM_IN);scrInspectionVo.setInspectionName(checkItemTreeVO.getClassifyName());}//流调筛查数据处理if (scrInspection.getType().equals(ScreeningConst.EPIDEMIC_SCREENING)){List<ScrInspectionQuestionVo> scrInspectionQuestionVos = this.selectByQuestionList(ScreeningConst.EPIDEMIC_SCREENING);scrInspectionQuestionVos.stream().forEach(s->{scrInspectionVo.setInspectionName(s.getTextName());});}return scrInspectionVo;}).collect(Collectors.toList());return inspectionVos;

其中selectByQuestionList和selectOne方法都是调用的其他服务的,全是在循环中调用的接口,这样对于数据库来说的话会有很大压力,所以经过我的整改,写了两个方法,代码奉上:

  @Override@ConverData(serviceId = ServiceNameConstants.KNOWLEDGE_SERVICE, table = "knowledge_check_item", key = "itemId", dbKey = "id", dbValue = "classify_name", value = "inspectionName")public List<ScrInspectionVo> selectByMcId(String id) {//根据医联体id查询出医联体下的所有数据List<ScrInspection> scrInspections = this.list(new LambdaQueryWrapper<ScrInspection>().eq(ScrInspection::getMcId, id).orderByDesc(ScrInspection::getSort));//项目筛查List<ScrInspection> project = scrInspections.stream().filter(x -> x.getType()==1).collect(Collectors.toList());//流调筛查List<ScrInspection> epidemiological= scrInspections.stream().filter(liu -> liu.getType()==0).collect(Collectors.toList());List<ScrInspectionVo> projectList = initPro(project);List<ScrInspectionVo> epList = initEp(epidemiological);List<ScrInspectionVo> vos = new ArrayList<ScrInspectionVo>(projectList);vos.addAll(epList);return vos;}List<ScrInspectionVo> initPro(List<ScrInspection> pro){if (CollUtil.isEmpty(pro)){return new ArrayList<>();}return pro.stream().map(p->{ScrInspectionVo scrInspectionVo = new ScrInspectionVo();BeanUtils.copyProperties(p,scrInspectionVo);return scrInspectionVo;}).collect(Collectors.toList());}List<ScrInspectionVo> initEp(List<ScrInspection> epidemiological){if (CollUtil.isEmpty(epidemiological)){return new ArrayList<>();}//获取到itemId列表List<String> epIds = epidemiological.stream().map(ScrInspection::getItemId).collect(Collectors.toList());FormListModel formListModel = new FormListModel();formListModel.setFormKeys(epIds);//返回问卷列表List<FormListVO> epList = remoteMessageApi.getFromList(formListModel, SecurityConstants.FROM_IN).getData();List<ScrInspectionVo> scrInspectionVos = epidemiological.stream().map(s -> {ScrInspectionVo scrInspectionVo = new ScrInspectionVo();BeanUtils.copyProperties(s, scrInspectionVo);for (FormListVO formListVO : epList) {if (s.getItemId().equals(formListVO.getFormKey())){scrInspectionVo.setInspectionName(formListVO.getTextName());}}return scrInspectionVo;}).collect(Collectors.toList());return scrInspectionVos;}