在Rails中存储上一年的旧数据?

您可以将活动报告存储在数据库或文件系统中。可在第一次请求存档活动时生成报告。

class Campaign < ActiveRecord::Base   
  # Campaign model has an attribute called report_file
  def report_file
    return nil unless expired?
    attributes['report_file'] ||= generate_report_file
  end

  def generate_report_file
    return nil if attributes['report_file']
    # Generate the report using Prawn PDF OR wickedPDF etc.
    # Update report_file attribute with the report file location
    # Return the file location
  end
end

class CampaignsController < ApplicationController
  before_filter :check_expiry, :only => :show
  def report
    if @campaign.report_file
      send_file(@campaign.report_file)
    else
      # handle error
    end
  end
  def show
  end
  def check_expiry
    @campaign = Campaign.find(params[:id])
    if @campaign.expired?
      render :report
    end
  end
end