socialforge/app/models/praise_tread_cache.rb

class PraiseTreadCache < ActiveRecord::Base
  attr_accessible :object_id,:object_type,:praise_num,:tread_num
  belongs_to :object, :polymorphic => true

  def plus(flag,num)
    case flag
    when 0
       self.update_attribute(:tread_num, self.tread_num.to_i + num)
    when 1
      self.update_attribute(:praise_num, self.praise_num.to_i + num)
    end
  end

  def minus(num)
    self.update_attribute(:praise_num, self.praise_num.to_i - num)
  end
end