需要得到轨数据连接表的has_many：通过 [英] Need data from rails join table, has_many :through

问题描述

我有3个表 - 用户，东西，如下。用户可以按照事情经过如下表，关联一个 USER_ID 与 things_id 。这意味着：

I have 3 tables - users, things, and follows. Users can follow things through the follows table, associating a user_id with a things_id. This would mean:

class User
  has_many :things, :through => :follows
end

class Thing
  has_many :users, :through => :follows
end

class Follow
  belongs_to :users
  belongs_to :things
end

所以我可以检索没有问题thing.users。我的问题是，如果在如下表，我有一个名为关系一栏，这样我就可以设置一个跟随者为管理员，我想有机会获得这层关系。因此，在一个循环中我可以这样做：

So I can retrieve thing.users with no problem. My issue is if in the follows table, I have a column named "relation", so I can set a follower as an "admin", I want to have access to that relation. So in a loop I can do something like:

<% things.users.each do |user| %>
  <%= user.relation %>
<% end %>

有没有一种方法，包括关系到原来的用户对象？我曾尝试：选择=＆GT; follows.relation，但它似乎并没有加入该属性。

Is there a way to include relation into the original user object? I have tried :select => "follows.relation", but it doesn't seem to join the attribute.

推荐答案

要做到这一点，你需要使用一个位SQL中的has_many。像这样的东西应该有希望的工作。
的has_many：用户：通过=＆GT; ：如下，：选择=＆GT; 用户。*，follows.is_admin为is_follow_admin

To do this you need to use a bit of SQL in the has_many. Something like this should hopefully work. has_many :users, :through => :follows, :select => 'users.*, follows.is_admin as is_follow_admin'

然后在循环，你应该能够访问
user.is_follow_admin

Then in the loop you should have access to user.is_follow_admin

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