为什么ActiveRecord has_many使用delete_all而不是destroy_all？

发布于 2024-08-18 02:25:08 字数 388 浏览 5 评论 0原文

我有一个有很多孩子的模型。我这样设置/删除子项：

mymodel.children_ids = [1,2,3]
mymodel.save #add the children
mymodel.children_ids = [1]
mymodel.save #remove children 2,3

这工作得很好，但我刚刚意识到没有在子项模型上调用任何回调（即 after_destroy）。

经过一番挖掘，发现正在执行的是 delete_all 函数，而不是 destroy_all。正如文档正确指出的那样，delete_all 函数不会触发回调，那么有没有办法改变这种行为呢？

谢谢。

原文

I have a model which has many children. I was setting/removing the children as such:

mymodel.children_ids = [1,2,3]
mymodel.save #add the children
mymodel.children_ids = [1]
mymodel.save #remove children 2,3

This works just fine, but I just realized that none of the callbacks (i.e. after_destroy) are not being called on the children model.

After some digging, it turns out that the delete_all function is being executed, rather than destroy_all. As the docs correctly state, the delete_all function does not fire off the callbacks, so is there anyway to change this behavior?

Thanks.

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挖个坑埋了你 2024-08-25 02:25:08

比如：

mymodel.children.find([2,3]).each {|c| c.destroy }

会完成这项工作。这不完全是你想要的，但我希望它有帮助。

Something like:

mymodel.children.find([2,3]).each {|c| c.destroy }

will do the job. It's not exactly what you wanted, but I hope it helps.

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撩人痒 2024-08-25 02:25:08

delete_all 正在执行...只是因为？ Rails 核心团队认为在这种情况下应该这样称呼。但是，您可以对模型的子项显式调用 destroy_all 方法，但不使用该类型的查询。看起来您是直接设置子 ID，而不是使用任何 build() 或 destroy() 方法。

是的，您可以覆盖其功能。您可以对其进行修补并将其放入 /vendor 中，并使用 destroy_all 重写相同的代码块。然后使用 send 命令将基本 ActiveRecord 功能替换为您自己的功能。

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倦话 2024-08-25 02:25:08

对于那些感兴趣的人，我添加了以下 Monkeypatch 来强制 has_many 通过执行 destroy_all，而不是 delete_all。可能有更好的方法，所以我愿意接受建议。

module ActiveRecord 
  module Associations
    class HasManyThroughAssociation < HasManyAssociation       
      def delete_records(records)
        klass = @reflection.through_reflection.klass
        records.each do |associate|
          klass.destroy_all(construct_join_attributes(associate)) #force auditing by using destroy_all rather than delete all
        end
      end
    end
  end
end

For those interested, I added the following monkeypatch to force the has_many through to perform a destroy_all, rather than delete_all. There might be a better way, so I'm open to suggestions.

module ActiveRecord 
  module Associations
    class HasManyThroughAssociation < HasManyAssociation       
      def delete_records(records)
        klass = @reflection.through_reflection.klass
        records.each do |associate|
          klass.destroy_all(construct_join_attributes(associate)) #force auditing by using destroy_all rather than delete all
        end
      end
    end
  end
end

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温馨耳语 2024-08-25 02:25:08

我在回调方面也遇到了类似的问题。使用 alias_method_chain 覆盖默认设置器解决了这个问题。

  def product_categories_with_destroy=(product_categories)
    unless new_record? 
      (self.product_categories - product_categories).each(&:destroy)
    end

    self.product_categories_without_destroy = product_categories
  end
  alias_method_chain :product_categories=, :destroy

有关alias_method_chain的更多详细信息：

http://yehudakatz.com/2009/03/ 06/alias_method_chain-in-models/

I had similar problem with callbacks. Solved it using alias_method_chain to override default setter.

  def product_categories_with_destroy=(product_categories)
    unless new_record? 
      (self.product_categories - product_categories).each(&:destroy)
    end

    self.product_categories_without_destroy = product_categories
  end
  alias_method_chain :product_categories=, :destroy

More details on alias_method_chain:

http://yehudakatz.com/2009/03/06/alias_method_chain-in-models/

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