View pulls up all table records instead of specific ID records, controller issue?

Question

I am trying to build a simple quiz app, I already have one table for questions and another for answers (answers each have a question_id tag to pull up the multiple choice options for each question).

I have listed out all my multiple choice questions on one page, and I want only the answers that correspond to each question to display below the question, however each MCQ is currently listing the full answer table instead of just the matching answers.

I think it has to do either with my view or controller code that's causing this behaviour (when I change the question ID in my controller to just a single question, the 4 possible answers appear correctly, but when I change it to @questions = Question.all, then the full answer table returns).

Or it might have to do with using <% @question_answers.each do |question_answers| %> wrongly.

My pages_controller.rb code:

class PagesController < ApplicationController
  def show
  end

  def home

  end

  def challenge
    @questions = Question.all
    @question_answers = QuestionAnswer.where(question_id: @questions.pluck(:id))
    # @questions = Question.where(id: 3)
  end
end

My view file at pages/challenge.html.erb:

<h1>Challenge</h1>

<% @questions.each do |question| %>
<div class="container">
    <p><%= question.question %></p>
    <form>
      <% @question_answers.each do |question_answers| %>
        <input type="radio" name="gender" value=<%= question_answers.answer %>><%= question_answers.answer %><br>
      <% end %>
      <input type="submit" value="Submit">
    </form>
</div>
<% end %>

I want only the answers that correspond to each question to display below the question, any ideas what I'm getting wrong here?

Answer 1

You are wrong with this code:

<% @question_answers.each do |question_answers| %>
  <input type="radio" name="gender" value=<%= question_answers.answer %>><%= question_answers.answer %><br>
<% end %>

question_answers is all records from answer table because you assigned it to QuestionAnswer.where(question_id: @questions.pluck(:id))

You should query only questions that belongs to answer. Assume you have two model and set up association like this:

class Question
  has_many :question_answers
end

class QuestionAnswer
  belongs_to :question
end

Then in your view you can get questions belongs to an answer like this:

<% @questions.each do |question| %>
<div class="container">
  ...
  <% question.question_answers.each do |question_answer| %>
    <input type="radio" name="gender" value=<%= question_answer.answer %>><%= question_answer.answer %><br>
  <%>
  ...
</div>
<% end %>

In controller, you only need:

@questions = Question.includes(:question_answers).all

includes(:question_answers) is used to avoid N+1 queries when loading answers for each question.

Answer 2

Have you specified the relationship between the models question and answer. If so, in the view try giving this

<% @questions.each do |question| %>
<div class="container">
    <p><%= question.question %></p>
    <form>
      <% question.question_answers.each do |question_answers| %>
        <input type="radio" name="gender" value=<%= question_answers.answer %>><%= question_answers.answer %><br>
      <% end %>
      <input type="submit" value="Submit">
    </form>
</div>
<% end %>

when you give question.question_answers.each the answers related to that question will be pulled.