滑轨| 链接共享应用| 数据库建模

Question

I am trying to learn Rails by building a link sharing app.

1) User can submit a Post along with a reference to other users who have created that post.

2) So, a post belongs to a user(who submitted it) and also other users (who created the post)

Currently, I have 2 tables

1) Users 2) Posts

class User < ActiveRecord::Base
  has_many :posts
end

class Post < ActiveRecord::Base
 belongs_to :submitted_user, class_name: 'User', foreign_key: 'user_id'
 #belongs to multiple other users who have created the post#
end

Should I use has_many through and create a join table PostCreators that has a user_id and post_id. In that case Can I write multiple has_many :posts?

class User
 has_many :posts #submitted_user in post
 has_many :posts, through: :post_creators 
end

class Post 
  belongs_to :submitted_user, class_name: 'User', foreign_key: 'user_id'
  has_many :creators, through: :post_creators
end

class PostCreator
  belongs_to :user
  belongs_to :post
end

Answer 1

class User < ActiveRecord::Base
  has_many :user_posts
  has_many :posts, through: :user_posts
end

class Post < ActiveRecord::Base
  belongs_to :submitted_user, class_name: 'User', foreign_key: 'submitted_user_id'
  has_many :user_posts
  has_many :posts, through: :user_posts
end

class UserPost < ActiveRecord::Base
  belongs_to :user
  belongs_to :post
end

Also write a migration to add submitted_user_id to Post table

p = Post.last

p.users => will return array of created users

p.submitted_user => will return submitter user object

Answer 2

是的，您必须创建“发布”和“用户联接”表，并添加关联has_many，以在联接表上存储其他数据。

Answer 3

I have done it like this

class User < ActiveRecord::Base
  has_many :user_posts
  has_many :posts, through: :user_posts
end

class Post < ActiveRecord::Base
  has_many :user_posts
  has_many :users, through: :user_posts
end

class UserPost < ActiveRecord::Base
  belongs_to :user
  belongs_to :post
  enum status: { submitter: 0, creators: 1 }
end

So, if I want to find out the creators of a post, I do

post = Post.first
UserPost.where(post: post).creators

By default, when a user submits a post, UserPost record of that user and post will be created with a enum status of 0.

When the submitter selects the post's creators, UserPost records will be created with that post, selected users and enum status of 1

I am not sure if this is the best way. Please comment if you think of an optimal way of doing this.