diff --git a/app/controllers/exercise_questions_controller.rb b/app/controllers/exercise_questions_controller.rb
index 77cc108b3..deb9b3157 100644
--- a/app/controllers/exercise_questions_controller.rb
+++ b/app/controllers/exercise_questions_controller.rb
@@ -223,7 +223,6 @@ class ExerciseQuestionsController < ApplicationController
           end
         end
         #试卷未发布时，当标准答案存在时，可修改标准答案内容，可增删标准答案，否则只能修改标准答案，不能增删标准答案
-        st_count = 0
         @exercise_answers_array = @exercise_question.exercise_standard_answers  #问卷的全部标准答案
         if standard_answer.present?
           if @exercise_question.question_type <= 2 #选择题/判断题，标准答案为一个或多个
@@ -232,7 +231,6 @@ class ExerciseQuestionsController < ApplicationController
             old_left_standard_choices = exercise_standard_choices - common_standard_choices # 以前的差集共同的，剩余的表示需要删掉
             new_left_standard_choices = standard_answer - common_standard_choices # 传入的标准答案差集共同的，剩余的表示需要新建
             if old_left_standard_choices.count > 0
-              st_count += 1
               @exercise_answers_array.standard_by_ids(old_left_standard_choices).destroy_all
             end
             if new_left_standard_choices.count > 0  #新建标准答案
@@ -258,7 +256,6 @@ class ExerciseQuestionsController < ApplicationController
 
             #删除多余的选项
             if old_ex_answer_choice_ids.count > new_ex_answer_choice_ids.count  #有减少的填空
-              st_count += 1
               delete_ex_answer_choice_ids = old_ex_answer_choice_ids - new_ex_answer_choice_ids
               old_ex_answer.standard_by_ids(delete_ex_answer_choice_ids).destroy_all
             end
@@ -284,7 +281,6 @@ class ExerciseQuestionsController < ApplicationController
                     ex_answer_pre[n-1].update(standard_option)
                   end
                   if new_add_choice.count > 0  #表示有新增的
-                    st_count += 1
                     new_add_choice.each do |i|
                       standard_option = {
                           :exercise_question_id => @exercise_question.id,
@@ -306,7 +302,6 @@ class ExerciseQuestionsController < ApplicationController
                     ex_answer_pre[index].update(standard_option)
                   end
                   if new_delete_choice.count > 0  #表示填空题的答案有删减的
-                    st_count += 1
                     new_delete_choice.each do |d|
                       ex_answer_pre[d-1].destroy
                     end
diff --git a/db/migrate/20190703072611_add_old_exercise_tiankong_choice_id.rb b/db/migrate/20190703072611_add_old_exercise_tiankong_choice_id.rb
new file mode 100644
index 000000000..9ad1429e2
--- /dev/null
+++ b/db/migrate/20190703072611_add_old_exercise_tiankong_choice_id.rb
@@ -0,0 +1,23 @@
+class AddOldExerciseTiankongChoiceId < ActiveRecord::Migration[5.2]
+
+  def up
+    #类型为3 的问题答案及标准答案更新exercise_choice_id 为1，即表示第一空
+    exercise_question_ids = ExerciseQuestion.where("question_type = 3").pluck(:id)
+    ExerciseAnswer.where(exercise_question_id: exercise_question_ids,exercise_choice_id: nil).update_all(exercise_choice_id:1)
+    ExerciseStandardAnswer.where(exercise_question_id: exercise_question_ids,exercise_choice_id: nil).update_all(exercise_choice_id:1)
+
+    exercise_bank_question_ids = ExerciseBankQuestion.where("question_type =3").pluck(:id)
+    ExerciseBankStandardAnswer.where(exercise_bank_question_id: exercise_bank_question_ids).update_all(exercise_bank_choice_id:1)
+  end
+
+  def down
+    #类型为3 的问题答案及标准答案更新exercise_choice_id 为1，即表示第一空
+    exercise_question_ids = ExerciseQuestion.where("question_type = 3").pluck(:id)
+    ExerciseAnswer.where(exercise_question_id: exercise_question_ids,exercise_choice_id: 1).update_all(exercise_choice_id:nil)
+    ExerciseStandardAnswer.where(exercise_question_id: exercise_question_ids,exercise_choice_id: 1).update_all(exercise_choice_id:nil)
+
+    exercise_bank_question_ids = ExerciseBankQuestion.where("question_type =3").pluck(:id)
+    ExerciseBankStandardAnswer.where(exercise_bank_question_id: exercise_bank_question_ids).update_all(exercise_bank_choice_id:nil)
+  end
+
+end