定义has_many self联接的表名吗？ [英] Defining table name for has_many self joins in rails?

问题描述

我希望设置嵌套注释，并希望使用自连接进行设置。

I wish to set up nested comments, and want to use self-join to set this up.

class Comment < ActiveRecord::Base

has_many :children, :class_name => 'Comment'

#...
end

现在，我将使用什么sql表结构来设置has_many自联接？

Now, what sql table structure would I use to set up the has_many self-join?

我假设是这样的：

comment_to_comments:
parent_id integer
child_id integer

我如何告诉rails使用此表？如何告诉rails parent_id是到达父级的外键，child_id是到达子级的外键？

How do I tell rails to use this table? How do I tell rails that parent_id is the foreign key to reach the parent and the child_id is the foreign key to reach the child?

推荐答案

create_table :comments do |t|
  t.integer :parent_id
end

class Comment < ActiveRecord::Base
  has_many :children, :class_name => "Comment", :foreign_key => :parent_id
  belongs_to :parent, :class_name => "Comment"

end

我建议您使用插件来实现此功能.like awesome_nested_set或acts_as_tree。

I suggest you use plugin to implement this feature.like awesome_nested_set or acts_as_tree.

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