1

app/controllers/exercise_controller.rb

@@ -74,21 +74,17 @@ class ExerciseController < ApplicationController
     #   end
     # end
     @is_teacher = User.current.allowed_to?(:as_teacher,@course) || User.current.admin?
-
+    ActiveRecord::Base.transaction do
       unless @is_teacher
         @exercise_user = ExerciseUser.where("user_id=? and exercise_id=?", User.current.id, @exercise.id).first
         if @exercise_user.nil?
           @exercise_user = ExerciseUser.create(:user_id => User.current.id, :exercise_id => @exercise.id, :start_at => Time.now, :status => false, :commit_status => 0)
-        if @exercise.exercise_level_settings.where("num != exercise_questions_count").count > 0
-          @exercise.create_user_question_list(@exercise_user.id)
-        end
-        # @exercise_user = ExerciseUser.where("user_id=? and exercise_id=?", User.current.id, @exercise.id).first
         elsif @exercise_user.start_at.nil?
+          @exercise_user.update_attributes(:start_at => Time.now)
+        end
         if @exercise.exercise_level_settings.where("num != exercise_questions_count").count > 0
           @exercise.create_user_question_list(@exercise_user.id)
         end
-        @exercise_user.update_attributes(:start_at => Time.now)
-      end
 
         @can_edit_excercise = can_edit_exercise @exercise, @exercise_user
         if !@can_edit_excercise && !@exercise_user.status
@@ -119,6 +115,8 @@ class ExerciseController < ApplicationController
       end
 
       @exercise_questions = @exercise.user_question_list @exercise_user.id
+    end
+
 
     # @percent = get_percent(@exercise,User.current)
     #@exercise_questions = @exercise.exercise_questions