提交次数默认值为空的数据处理

db/migrate/20160114131753_default_changeset.rb

@@ -0,0 +1,9 @@
+class DefaultChangeset < ActiveRecord::Migration
+  def up
+    pss = ProjectScore.where("changeset_num is ?", nil)
+    pss.update_all(:changeset_num => false)
+  end
+
+  def down
+  end
+end