Why do my model attributes save out of order? - ruby-on-rails

Question

This happens particularly often when I try and update a model.
I have a quiz app, and I add a quiz using this form:
<%= form_for(#quiz) do |f| %>
<% if #quiz.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#quiz.errors.count, "error") %> prohibited this quiz from being saved:</h2>
<ul>
<% #quiz.errors.full_messages.each do |message| %>
<li><%= message %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="field">
<%= f.label :name %><br>
<%= f.text_field :name %>
</div>
<div class = 'field'>
<%= f.label :difficulty, "Difficulty of Quiz, 1 to 3 with 3 being most difficult" %>
<%= f.text_field :difficulty %>
</div>
<div class="field">
<%= f.label :for_unsubscribed, "Check to have this quiz be visible to logged in but unsubscribed users" %>
<%= f.check_box :for_unsubscribed %>
</div>
<%= f.fields_for :questions do |question_attribute| %>
<div class = 'inner-c'>
<p>
<%= question_attribute.label :content, "Question" %> <span><b><%= question_attribute.index + 1 %></b></span> <br/>
<%= question_attribute.text_area :content, :cols => 100, :rows => 4 %>
</p>
<p>
<%= question_attribute.label :explanation, "Answer Explanation" %> <br/>
<%= question_attribute.text_area :explanation, :cols => 100, :rows => 6 %>
</p>
<%= question_attribute.label :_destroy, "Remove Question"%>
<%= question_attribute.check_box :_destroy %><br/>
<%= question_attribute.label :passage, "Reference Passage" %> <br/>
<%= question_attribute.text_area :passage, :rows => 3, :class => 'passage-input' %>
<%#= question_attribute.label :question_explanation, "Question Explanation" %>
<%#= question_attribute.text_area :question_explanation, :rows => 10 %>
</p>
<%= question_attribute.fields_for :answers do |answer_attribute| %>
<p>
<%= answer_attribute.label :content, "Answer" %>
<%= answer_attribute.text_field :content %>
<%= answer_attribute.label :correct_answer, "Check to indicate correct answer", :class => 'inline' %>
<%= answer_attribute.check_box :correct_answer, :class => 'inline'%>
</p>
<% end %>
</div> <!-- inner-c -->
<% end %>
<div class="actions">
<%= f.submit %>
</div>
<% end %>
A new form would be generated by the controller like so:
def new
#quiz = Quiz.new
50.times do
question = #quiz.questions.build
5.times { question.answers.build }
end
end
Taking advantage of using nested models, where a Quiz has_many Questions which has_many Answers.
The problem is -- when I create a quiz (with 50 questions), then I try and update the quiz afterwards, to fix a mistake for example, The questions move out of order. Question 43 and Question 1 might switch places. I absolutely need the questions to stay in the same order after I update them but I can't figure out how to make this happen. Any ideas?

Answer 1

Generally in RDBMS order is not specified by default, unless you explicitly state it. Therefore if you don't specify the order you can get results in any order an that is an expected behaviour.
But according to your description question 43 swapped with question 1 after an update, so I can think you are ordering them by an updated_at timestamp. Try to order explicitly order questions by id – id is [normally] a PrimaryKey and it never changes, so your questions will stay in order.