如何在has_many的中间模型中创建has_many关联：以最佳方式通过关联Rails

Question

What I want is to have a Profile where I can create contents, each content could have many videos, many images and so on. That's why I'm thinking about videos and images as different tables. But I'd like to know if a video belongs to a specific profile or content without writing complicated queries.

I have the following models, with has_many :through association

class Profile < ApplicationRecord
  has_many :contents
  has_many :videos, through: :contents
end

class Content < ApplicationRecord
  belongs_to :profile
  belongs_to :video
end

class Video < ApplicationRecord
  has_many :contents
  has_many :profiles, through: :contents
end

and the following migrations

create_table :contents do |t|
  t.string :name
  t.text :description
  t.references :video, foreign_key: true
  t.references :profile, foreign_key: true
end

create_table :profiles do |t|
  t.integer :profile_type
  t.references :user, foreign_key: true
end

create_table :videos do |t|
  t.string :name
  t.string :file
  t.string :link
end

So far, my problem is that I can have only one Video per Content. How can I store many videos in Content (the intermediate table) keeping the has_many through association?

Since I want to have different kinds of contents, that implies they would be extra tables and I would like to get some ideas that help me to improve this approach

Note: I was reading this documentation, http://guides.rubyonrails.org/association_basics.html#the-has-many-through-association

Answer 1

There is a conflict of "truthness" between your

Profile where I can create contents, each content could have many videos, many images and so on

and your actual code implementation being that:

• you state you want:
  • Profile has many Contents
  • Content has many Videos
• ...but your code is:
  • Profile has many Contents
  • Video has many Contents

Therefore, if I understood it correctly, and assuming that you want to change your "code" into what you "want", then:

TL;DR:

class Profile < ApplicationRecord
  has_many :contents
  has_many :videos, through: :contents
end

class Content < ApplicationRecord
  belongs_to :profile
  has_many :videos
end

class Video < ApplicationRecord
  belongs_to :content
end

and your schema should look like:

create_table :contents do |t|
  t.string :name
  t.text :description
  t.references :profile, foreign_key: true
end

create_table :profiles do |t|
  t.integer :profile_type
  t.references :user, foreign_key: true
end

create_table :videos do |t|
  t.string :name
  t.string :file
  t.string :link
  t.references :content, foreign_key: true
end

• Above code should answer your other question:

  How can I store many videos in Content

  ... because a Content record now has many Videos