protected static function write_revert($name, $type, $file)
	{
		// remove the migration just run
		\DB::delete(static::$table)
			->where('name', $name)
			->where('type', $type)
			->where('migration', $file)
		->execute(static::$connection);

		// remove the file from the list of run migrations
		if (($key = array_search($file, static::$migrations[$type][$name])) !== false)
		{
			unset(static::$migrations[$type][$name][$key]);
		}

		// make sure the migrations are in the correct order
		sort(static::$migrations[$type][$name]);

		// and save the update to the config file
		\Config::set('migrations.version.'.$type.'.'.$name, static::$migrations[$type][$name]);
		\Config::save(\Fuel::$env.DS.'migrations', 'migrations');
	}