Question

I’m trying to figure out how to do a table join in one of my models.

There are points, questions, and users.

point.rb

class Point < ActiveRecord::Base
    belongs_to :user
    belongs_to :question
end

question.rb

class Question < ActiveRecord::Base
    has_many :points
end

user.rb

class User < ActiveRecord::Base

In my Points controller I am doing this:

def index
    @points = Point.all
    @user_points = Point.where('user_id' => current_user)
end

And in my points/index view:

    <% @user_points.each do |user_point| %>
  <tr>
    <td><%= current_user.name %></td>
    <td><%= user_point.question_id %></td>
    <td><%= user_point.correct_answer %></td>
    <td><%= user_point.user_answer %></td>
  </tr>
<% end %>

I need to access the name of each question in the questions table (I have the question id available in my view. I’m a n00b to rails, and can’t figure out how to this with the documentation.

Answer 1

Take a look at the Rails Guides, especially these two:

1. http://guides.rubyonrails.org/association_basics.html
2. http://guides.rubyonrails.org/active_record_querying.html

I think you should be able to set this in your model:

class User < ActiveRecord::Base
    has_many :points, :through => :questions
end

in your controller say @user_points = current_user.points

in your view. This should already work with your current code!

<% @user_points.each do |user_point| %>
    <td><%= user_point.question.name %></td>
<% end %>