获取通知科目和班级完善

sapi/src/main/resources/mapper/notice/NoticeUserMapper.xml

         select nu.gradeid,nu.classid,nu.subjectid
         ,if(nu.classid is not null,(select concat(c.classname,'_',c.classtype,'-',c.classorder) from t_class c where c.classid=nu.classid)
             ,(select concat(s.subjectname,'_',s.subjectorder) from t_subject s where s.subjectid=nu.subjectid))username
-        from t_notice_user nu where noticeid=#{noticeid}
+        from t_notice_user nu where noticeid=#{noticeid} and (nu.classid is not null or nu.subjectid is not null)
         group by nu.gradeid,nu.classid,nu.subjectid
     </select>
 </mapper>