Ruby on Rails：如何将对象从一个类别复制到另一个类别

Question

我正在尝试将一些最新的收件人（订阅者）复制到我的时事通讯应用中的新类别。我在 Rails 控制台中运行了以下代码行，但没有将收件人复制到新类别，而是将最新的 10 个收件人移动到新类别。看起来recipient.clone 不起作用。我正在使用 Ruby v2.0.0 和 Rails v3.2.11。

recipients = Recipient.where(category_id: 54).order('created_at DESC').take(10)
recipients.each{ |recipient| 
  @recipient_clone = recipient.clone
  @recipient_clone.category_id=63
  @recipient_clone.save
}

更新：

我试过了

recipients.each{ |recipient| 
  recipient.freeze
  @recipient_clone = recipient.dup
  @recipient_clone = @recipient_clone.category_id=63
  @recipient_clone.save
}

但它给出了NoMethodError: private method 'initialize_dup' called 错误。

Answer 1

这可能不是最干净的方法，但它应该可以工作:)

recipients = Recipient.where(category_id: 54).order('created_at DESC').take(10)
recipients.each{ |recipient| 
  @recipient_clone = Recipient.new(recipient.attributes.except(:id))
  @recipient_clone.category_id=63
  @recipient_clone.save
}