考试缺考学生详情

sexam/src/main/resources/mapper/paperstudent/EPaperStudentMapper.xml

@@ -342,7 +342,7 @@
     <select id="listQkDetail" resultType="java.util.Map">
         select ec.classid,ec.classname,ec.classnum
         ,count(distinct case when eps.sstate=3 then eps.epsid else null end)qknum
-        ,group_concat(case when eps.sstate=3 then eps.studentid else null end)userids
+        ,ifnull(group_concat(case when eps.sstate=3 then eps.studentid else null end),'')userids
         ,truncate(count(distinct case when eps.sstate=3 then eps.epsid else null end)*100/count(*),2)qkrate
         from e_paper_student eps left join e_class ec on eps.examid=ec.examid and eps.classid=ec.classid
         where eps.epid=#{epid} group by eps.classid order by ec.ecid