diff --git a/db/migrate/20151020021234_update_course_activity.rb b/db/migrate/20151020021234_update_course_activity.rb
new file mode 100644
index 000000000..595b0d333
--- /dev/null
+++ b/db/migrate/20151020021234_update_course_activity.rb
@@ -0,0 +1,23 @@
+class UpdateCourseActivity < ActiveRecord::Migration
+  def up
+    count = CourseActivity.all.count / 30 + 2
+    transaction do
+      for i in 1 ... count do i
+      CourseActivity.page(i).per(30).each do |activity|
+        if activity.course_act
+          if activity.course_act_type == 'Poll'
+            if activity.course_act.polls_status == 1
+              activity.destroy
+            end
+          end
+        else
+          activity.destroy
+        end
+      end
+      end
+    end
+  end
+
+  def down
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 41efc5698..4aa12f627 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20151020014759) do
+ActiveRecord::Schema.define(:version => 20151020021234) do
 
   create_table "activities", :force => true do |t|
     t.integer  "act_id",                                  :null => false