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我有两个课程：Topic和Buy::Topic。后者是前者的子类，通过外键 ( Buy::Topic.topic_id == Topic.id)。所以本质上这是使用类表继承模式。

Buy::Topic有自己的和指向父对象id的外键。topic_idTopic

但是，我想确保 id与来自父级的 idBuy::Topic相同，如下所示：topic_id

#<Topic id: 22598>和 #<Buy::Topic id: 22598, topic_id:22598

这在 Rails 中可行吗？这对于 SEO 目的更好，并且可以更轻松地处理 Cancan 的load_and_authorize_resource（有时 cancan 使用两者的错误 id 来查找东西）。

UDPATE：

这个模式已经设置并完成了很长时间，所以现在不太可能将其更改为 STI。

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2 回答 2

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Doing this will actively destroy your CTI and might even create an anti-pattern!

My argument is that if,

Buy::Topic.id == Buy::Topic.topic_id == Topic.id

then you create a one-to-one relationship between Buy::Topic and Topic.

This means that no other class can be composed of Buy::Topic because the id could clash with some Topic.id.

Since Buy::Topic is a subclass of Topic, you really only have a single conceptual entity now. Except you have two tables and some crazy indexes to get you there.

于 2012-03-06T04:32:20.133 回答
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伙计，这没关系，只需调用您的列 topic_parent_id 并创建如下关联：

belongs_to :parent, :class_name => '主题', :foreign_key => 'topic_parent_id'

于 2012-03-06T09:15:37.523 回答