diff --git a/app/helpers/exercises_helper.rb b/app/helpers/exercises_helper.rb
index 6eb798d9a..9ac02c82a 100644
--- a/app/helpers/exercises_helper.rb
+++ b/app/helpers/exercises_helper.rb
@@ -115,10 +115,12 @@ module ExercisesHelper
         right_users_count = 0  #该问题的回答正确的人数
 
         #计算每个问题的答案人数
-        user_ids.each do |user_id|
-          answer_choice_array = effictive_users.where(user_id:user_id)&.map {|s| s.exercise_choice.choice_position}.uniq
-          if answer_choice_array.sort == standard_answer
-            right_users_count += 1
+        effictive_users.transaction do
+          user_ids.each do |user_id|
+            answer_choice_array = effictive_users.where(user_id:user_id)&.map {|s| s.exercise_choice.choice_position}.uniq
+            if answer_choice_array.sort == standard_answer
+              right_users_count += 1
+            end
           end
         end
         percent = effictive_users_count > 0 ? (right_users_count / effictive_users_count.to_f).round(3)*100 : 0.0