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    <title>orichi (orichi.wang)</title>
    <link>https://ruby-china.org/orichi</link>
    <description></description>
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    <item>
      <title>需要一个模块给所有 model 添加一个方法</title>
      <description>&lt;p&gt;class User &amp;lt; ActiveRecord::Base
end
class Post &amp;lt; ActiveRecord::Base
end&lt;/p&gt;

&lt;p&gt;module A
 #TODO 
 # add a method like virtual_id
 # this virtual_id find the last record in db and add 1&lt;/p&gt;

&lt;p&gt;end&lt;/p&gt;

&lt;p&gt;class ActiveRecord::Base
    include A
end&lt;/p&gt;

&lt;p&gt;user = User.new
user.virtual_id = user.id should be User.last.id.suc 
post = Post.new
post.virtual_id = post.id should be Post.last.id.suc
加入数据库最后一条的 id 是“post-orichi-142”
那么 virtual_id 应该是“post-orichi-143”
怎么在 module A 里定义方法 virtual_id, 使得 user 和 post 可以获取一个虚拟的 id&lt;/p&gt;</description>
      <author>orichi</author>
      <pubDate>Thu, 08 Nov 2012 16:52:34 +0800</pubDate>
      <link>https://ruby-china.org/topics/6618</link>
      <guid>https://ruby-china.org/topics/6618</guid>
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