删除不存在的留言动态

db/migrate/20151224090313_delete_journals_message.rb

@@ -0,0 +1,17 @@
+class DeleteJournalsMessage < ActiveRecord::Migration
+  def up
+    count = JournalsForMessage.all.count / 30 + 2
+    transaction do
+      for i in 1 ... count do
+        JournalsForMessage.page(i).per(30).each do |message|
+          if !message.m_parent_id.nil? and message.parent.nil?
+            message.destroy
+          end
+        end
+      end
+    end
+  end
+
+  def down
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20151218110033) do
+ActiveRecord::Schema.define(:version => 20151224090313) do
 
   create_table "activities", :force => true do |t|
     t.integer  "act_id",                                  :null => false
@@ -1569,7 +1569,6 @@ ActiveRecord::Schema.define(:version => 20151218110033) do
   end
 
   add_index "student_works", ["homework_common_id", "user_id"], :name => "index_student_works_on_homework_common_id_and_user_id"
-  add_index "student_works", ["homework_common_id"], :name => "index"
 
   create_table "student_works_evaluation_distributions", :force => true do |t|
     t.integer  "student_work_id"