Ruby 如何克隆具有多个关联的 类栏

您可以编写

Bar.new（Bar.attributes.reject\u at（“id”，“foo\u id”））

class Bar < ActiveRecord::Base
  belongs_to :foo
end

class Foo < ActiveRecord::Base
  has_many :bars
end

Foo oldFoo = Foo.new

Foo foo = Foo.new
foo.bars << oldFoo.bars.all.collect { |bar| bar.clone }

foo.bars << oldFoo.bars.all.collect { |bar| Bar.new(bar.attributes) }

class Hash
 def select_at(*s_keys)
    Hash[s_keys.zip(values_at(*s_keys))]
  end

  def reject_at(*r_keys)
    select_at(keys - r_keys)
  end
end