克隆rails中的记录，是否可以克隆关联和深层复制？

I'm .clone -ing a record in rails...

我是。在铁路上抓住一条记录......

  new_blerg = Blerg.find(1).clone

This record has loads and loads of associations, and those associations even have associations.

此记录具有负载和负载的关联，并且这些关联甚至具有关联。

Is there a way to deep-copy a record and clone it so it is cloned with all of those associations too?

有没有办法深度复制记录并克隆它，以便克隆所有这些关联呢？

3 个解决方案

#1

You may get some good use out of the Amoeba gem for ActiveRecord 3.2.

对于ActiveRecord 3.2，您可以从Amoeba gem中获得一些好处。

It supports easy and automatic recursive duplication of has_one, has_many and has_and_belongs_to_many associations, field preprocessing and a highly flexible and powerful configuration DSL that can be applied both to the model and on the fly.

它支持has_one，has_many和has_and_belongs_to_many关联的简单和自动递归复制，字段预处理以及可以同时应用于模型和动态的高度灵活且功能强大的配置DSL。

be sure to check out the Amoeba Documentation but usage is pretty easy...

请务必查看Amoeba文档，但使用非常简单......

just

只是

gem install amoeba

or add

或添加

gem 'amoeba'

to your Gemfile

到您的Gemfile

then add the amoeba block to your model and run the dup method as usual

然后将变形虫块添加到模型中并像往常一样运行dup方法

class Post < ActiveRecord::Base
  has_many :comments
  has_and_belongs_to_many :tags

  amoeba do
    enable
  end
end

class Comment < ActiveRecord::Base
  belongs_to :post
end

class Tag < ActiveRecord::Base
  has_and_belongs_to_many :posts
end

class PostsController < ActionController
  def some_method
    my_post = Post.find(params[:id])
    new_post = my_post.dup
    new_post.save
  end
end

Your new post should have all the tags that were originally associated with it, and all the comments should be duplicated as well. You can disable the duplication of various records through the DSL, which you can read about in the documentation, but for example, if you wanted to keep the tags, but not the comments you could do something like this:

您的新帖子应该包含最初与之关联的所有标记，并且所有评论也应该重复。您可以通过DSL禁用各种记录的复制，您可以在文档中阅读这些记录，但是，例如，如果您想保留标记，而不是注释，则可以执行以下操作：

class Post < ActiveRecord::Base
  has_many :comments
  has_and_belongs_to_many :tags

  amoeba do
    include_field :comments
  end
end

or using the exclusive syntax

或使用独家语法

class Post < ActiveRecord::Base
  has_many :comments
  has_and_belongs_to_many :tags

  amoeba do
    exclude_field :comments
  end
end

or by specifying which field types to recognize (and thusly copy)

或者通过指定要识别的字段类型（从而复制）

class Post < ActiveRecord::Base
  has_many :comments
  has_and_belongs_to_many :tags

  amoeba do
    recognize :has_and_belongs_to_many
  end
end

each of these various options should result in re-associating the new post with the same tags as the old post, but without duplicating the comments.

这些不同选项中的每一个都应该导致重新关联新帖子与旧帖子相同的标签，但不会重复评论。

Amoeba will also automatically recurse in to child records if you enable them

如果启用，Amoeba也会自动递归到子记录中

class Post < ActiveRecord::Base
  has_many :comments

  amoeba do
    enable
  end
end

class Comment < ActiveRecord::Base
  belongs_to :post
  has_many :ratings

  amoeba do
    enable
  end
end

class Rating < ActiveRecord::Base
  belongs_to :comment
end

You can also prefix fields with some extra data to indicate uniqueness

您还可以在字段前添加一些额外数据以指示唯一性

class Post < ActiveRecord::Base
  has_many :comments

  amoeba do
    enable
    prepend :title => "Copy of "
  end
end

and in addition to prepend you can also append to or run a regex on a given field

除了前置之外，您还可以在给定字段上附加或运行正则表达式

Enjoy! :)

请享用！ :)

#2

You'd need to write your own clone_with_associations method which goes through a specific listed set of associations. Theoretically you could write something generic which uses reflect_on_all_associations but you would need to do the same on the associated objects, and this would inevitably end up creating a loop that generates an infinite amount of records.

您需要编写自己的clone_with_associations方法，该方法通过特定列出的关联集。从理论上讲，你可以编写一些使用reflect_on_all_associations的泛型，但你需要在关联的对象上做同样的事情，这将不可避免地最终创建一个生成无限量记录的循环。

So, just write your own. Something like

所以，只需编写自己的。就像是

  #in Blerg
  has_many :foos
  has_many :bars #bars also have many chickens which we want to copy over as well
  def clone_with_associations
    new_blerg = self.dup
    new_blerg.save
    #simple association
    new_blerg.foos = self.foos
    #two-level association 
    self.bars.each do |bar|
      new_bar = bar.clone
      new_bar.save
      new_bar.chickens = bar.chickens 
      new_blerg.bars << bar
    end
    new_blerg
  end

Now you can do

现在你可以做到

@new_blerg = Blerg.find(1).clone_with_associations

#3

Equally, this gem seems to work well: https://github.com/moiristo/deep_cloneable, and is pretty easy to use.

同样，这个宝石似乎运作良好：https：//github.com/moiristo/deep_cloneable，并且非常容易使用。

Just

只是

gem ‘deep_cloneable’, ‘~> 1.4.0’

宝石'deep_cloneable'，'〜> 1.4.0'

and then:

接着：

pirate.deep_clone :include => :mateys

pirate.deep_clone：include =>：mateys

#1