虽然使用在的has_many关系时访问额外的属性在连接表 [英] Access extra attributes in join table when using though in has_many relationship

问题描述

我正在考虑加入的has_many关系之间的一些额外的属性。

I was considering adding some extra properties between a has_many relationship.

例如，我有一个用户表，组表。用户可以通过加入群：通过的has_many关系。我想补充的该组中的用户的角色的属性。

For example, I have a Users table, and a Group table. Users can join groups via a :through has_many relationship. I want to add the property of the 'role' of the user in that group.

create_table "groupization", :force => true do |t|
    t.integer  "user_id"
    t.integer  "group_id"
    t.string  "role"
    t.datetime "created_at",                     :null => false
    t.datetime "updated_at",                     :null => false
  end

我在想，我怎么能进入角色属性。我的想法是这样的：

I was wondering, how can I access the role attribute. I was thinking something like:

user.groups[0].role 

那是一个正确的做法？我知道的语法错误（我试过）;将正确的语法是什么样的？谢谢！

Is that a correct approach? I know the syntax is wrong (I tried it); what would the correct syntax be like? Thanks!

推荐答案

在您的用户模型中，你必须是这样的：

In your User model, you'll have something like:

class User < ActiveRecord::Base
  has_many :groupizations
  has_many :groups, :through => :groupizations
end

您只希望通过在控制台中的has_many 关系 groupizations 这样的访问角色信息。

You'd access the role information just through the has_many relationship to groupizations like this in the console.

foo = User.first
bar = foo.groupizations.first
bar.role

假设你对第一个用户groupizations。

Assuming you had groupizations on the first user.

使用一个特定的用户/组的关系，可以这样做：

Getting a specific user/group relationship could be done like this:

Groupizations.where("group_id = ? and user_id = ?", group.id, user.id)

然后从那里你可以得到你所寻找的角色。

Then from there you could get the role you were looking for.

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