调整

app/models/exercise.rb

@@ -72,7 +72,7 @@ class Exercise < ApplicationRecord
     # 有分班权限的统计管理的分班且已发布的学生情况
     if teacher_course_groups.exists?
       group_ids = teacher_course_groups.pluck(:course_group_id)
-      ex_users = all_student_works.joins("join course_members on student_works.user_id=course_members.user_id").
+      ex_users = ex_users.joins("join course_members on student_works.user_id=course_members.user_id").
           where(course_members: {course_group_id: group_ids})
     end
     ex_users