Merge branch 'dev_v2.2.0' into release_v2.2.0

merge

distributed-print-business/src/main/resources/mapper/TCStatisticsMapper.xml

@@ -10,14 +10,11 @@
         t.teacherName,
         t.clazzId,
         t.clazzName,
-        t.paperNumber,
+        IF(t.examStudentCount = 0,null,t.paperNumber) as paperNumber,
         t.printPlanId,
-        t.printPlanName,
+        IF(t.examStudentCount = 0,null,t.printPlanName) as printPlanName,
         t.examStudentCount,
-        case
-        when t.examStudentCount = 0 then 0
-        else t.examStudentCount + (t.drawCount * t.backupCount)
-        end printSum,
+        IF(t.examStudentCount = 0,0,t.examStudentCount + (t.drawCount * t.backupCount)) as printSum,
         t.status
         from
         (