ruby-on-rails - ActiveRecord::Base 上的 alias_method 导致 NameError

Question

我有一个直接从 ActiveResource::Base 继承的模型，我正在尝试为记录表中的大部分列运行 alias_method，但结果是一个 NameError:

NameError: undefined method address_line_1' for class
LeadImport::Base'

但我可以访问属性:

LeadImport::Base.new.address_line_1 #=> nil (not error)

我的类(class)有一个名为 address_line_1 的表列，所以我没有看到问题。

class LeadImport::Base < ActiveRecord::Base
    alias_method :address_1, :address_line_1
end

规范:Ruby 1.8.7、Rails 2.3.8

Answer 1

根据我发现的一个网站，您应该改用 alias_attribute:

The problem is that ActiveRecord doesn't create the accessor methods on the fly until the database connection is live and it has parsed the table schema. That's a long time after the class has been loaded.

class LeadImport::Base < ActiveRecord::Base
  alias_attribute :address_1, :address_line_1
end