Query from db only once despite method being called many times - php

Question

I am trying to create a Poll (quiz) app, now I am doing a functionality that gets random questions from the database and returns in a poll (test)
I am displaying the answers 1 by 1 and when a user clicks submit answer a request is ran and the next answer is displayed
The problem is that every time a user submits the controller gets called again and the db query as well (when he clicks the next question button
This means that the query will get different random questions now and because of that same questions appears twice sometimes
I want to make sure that the query that gets the questions only gets called once
Model:
private $random_questions;
public function getRandomQuestions($questions_count)
{
if (!$this->random_questions)
{
$this->random_questions = Question::orderByRaw('RAND()')->take($questions_count)->get();
}
return $this->random_questions;
}
public function nextQuestionLink($questions_count, $question_number) {
$nextQuestionLink = [];
if ($questions_count != $question_number && $questions_count > $question_number) {
$nextQuestionLink['url'] = '/polls/random/'.$questions_count.'/'.++$question_number;
$nextQuestionLink['text'] = 'Следващ въпрос';
$nextQuestionLink['class'] = 'btn-default';
} else {
$nextQuestionLink['url'] = '/result';
$nextQuestionLink['text'] = 'Приключи';
$nextQuestionLink['class'] = 'btn-primary';
}
return $nextQuestionLink;
}
Controller:
public function getRandomQuestions($questions_count, $question_number)
{
$question = Question::Instance();
$questions = $question->getRandomQuestions($questions_count);
$nextQuestionLink = $question->nextQuestionLink($questions_count,
$question_number);
return view('polls.random_questions_poll')->with([
'question' => $questions[$questions_count-1],
'next' => $nextQuestionLink,
]);
}
View:
#section('content')
<div id="quiz-wrapper">
<h1>{{ $question->question }}</h1>
{!! Form::open(array( 'id' => 'message')) !!}
{!! csrf_field() !!}
#foreach($question->answers->shuffle() as $answer)
<h3>
<div class="form-group">
<div class="radio">
{{Form::radio('result', "$question->id-$answer->id") }}
{{ Form::label('result', $answer->name) }}
</div>
</div>
</h3>
#endforeach
<a class="next-question-button btn {{ $next['class'] }}" href="{{ $next['url'] }}" style="display: block;" role="button">{{ $next['text'] }}</a>
<p id="validation-error-container"></p>
{!! Form::close() !!}
</div>
#endsection

Answer 1

Since php by default is stateless, you will need to store the initial set of questions in persistent storage and retrieve them from that for all later requests.
You can do this quite succinctly with sessions in your controller:
public function getRandomQuestions($questions_count, $question_number)
{
//attempt to retrieve from session
$questions = session('questions', function(){
//if not found in session, generate from DB,
$questions = Question::Instance()->getRandomQuestions($questions_count);
//and store in session for next request.
session(['questions' => $questions]);
return $questions;
});
$nextQuestionLink = $question->nextQuestionLink($questions_count,
$question_number);
return view('polls.random_questions_poll')->with([
'question' => $questions[$questions_count-1],
'next' => $nextQuestionLink,
]);
}