如何在 rails 上的多个表中创建关系？

Question

I'm new to rails and learning relationship between tables. This is what I want to create. Users wont be able to post into classes or videos just add them to their table.

example: I'm a student and I sign up for a user account. Then I choose the classes I want HTML and CSS. And then I'm only able to watch the videos inside those classes.

Users->classes->videos

(USERS)
username
password
classes - signs up for multiple classes

(classes)
HTML
CSS
Javascript
PHP

(inside of each class theres videos)
video1
video2
video3

Answer 1

Your relationship should be like has_many

User.rb
 has_many :classes
 has_many :videos, through: classes

Class.rb
 has_many :videos
 belongs_to :user

Video.rb
 belongs_to :class
 belongs_to :user

To apply this associations automatically you can use nested form structure

Here is link for that.

https://github.com/ryanb/nested_form

http://railscasts.com/episodes/196-nested-model-form-revised?view=comments

Thanks