迁移文件调整

db/migrate/20190515070751_migrate_exercise_user_questions.rb

@@ -1,6 +1,6 @@
 class MigrateExerciseUserQuestions < ActiveRecord::Migration
   def up
-    exercises = Exercise.where("id > 900")
+    exercises = Exercise.where("id > 1000")
 
     exercises.each do |exercise|
       if exercise.exercise_level_settings.where("num != exercise_questions_count").size > 0