fix

zhongzheng-system/src/main/java/com/zhongzheng/modules/grade/service/impl/ClassGradeUserServiceImpl.java

@@ -1859,7 +1859,7 @@ public class ClassGradeUserServiceImpl extends ServiceImpl<ClassGradeUserMapper,
                         if(Validator.isNotEmpty(photoList)&&photoList.size()>0){
                             classPeriodSectionVo.setStudyStartTime(photoList.get(0).getCreateTime());
                         }
-                        if(startTotalTime==0L||startTotalTime.longValue()>classPeriodSectionVo.getStudyStartTime().longValue()){
+                        if((startTotalTime==0L&&Validator.isNotEmpty(classPeriodSectionVo.getStudyStartTime()))||(Validator.isNotEmpty(classPeriodSectionVo.getStudyStartTime())&&startTotalTime.longValue()>classPeriodSectionVo.getStudyStartTime().longValue())){
                             startTotalTime = classPeriodSectionVo.getStudyStartTime();
                         }
                         if(endTotalTime==0L||(Validator.isNotEmpty(classPeriodSectionVo.getStudyEndTime())&&endTotalTime.longValue()<classPeriodSectionVo.getStudyEndTime().longValue())){