迁移文件

db/migrate/20150911064528_alter_user_activities.rb

@@ -0,0 +1,26 @@
+class AlterUserActivities < ActiveRecord::Migration
+  def up
+    count = UserActivity.all.count / 30 + 3
+    transaction do
+      for i in 1 ... count do i
+        UserActivity.page(i).per(30).each do |activity|
+          if activity.act_type == 'Message'
+            if activity.act
+              unless activity.act.parent_id.nil?
+                parent_act = UserActivity.where("act_id = #{activity.act.parent.id} and act_type='Message'").first
+                parent_act.created_at = activity.act.parent.children.maximum("created_on")
+                parent_act.save
+                activity.destroy
+              end
+            else
+              activity.destroy
+            end
+          end
+        end
+      end
+    end
+  end
+
+  def down
+  end
+end