php - pass variables through pages and changing it when go back - php

Question

I'm making a web project in php and I have a small problem with understanding how I can get the variables to the next page after clicking on a button.
Concept
The concept is simple, - Questions asked by users(with title, the question, author, etc..) and other users can reply a specific question. So the idea is to pass all the info of the particular question into the page were it can be answer.
The most logical solution that I thought saving all the info of the post into $_SESSION so it would be more easy to pass to the second page(I think), but the problem is that when the user choose to go back to the previous page all the $_SESSiON should be destroyed if the user chooses another question to answer.
Problem:
I'm struggling to get that system working
side note:
Can it be made by using ajax?
What is the best system for this type os cases?
CODE
function display_perguntas(){
require 'dbh.inc.php';
$userID = $_SESSION['userID'];
$sql = "SELECT * from forum_pergunta where disciplinaID IN (select disciplinaId from users_disciplinas where userID = $userID) AND userID = $userID";
$stmt = mysqli_stmt_init($conn);
$result = mysqli_query($conn, $sql);
while($row = mysqli_fetch_assoc($result)){
echo '<div class="container">
<h2>Questions from my subjects</h2><br>
<div class="row">
<div class="col-xl-2 col-lg-3 col-sm-5">
Title: <strong>'.$row['title'].'</strong>
</div>
<div class="col-lg-3 col-xl-5 col-sm-5">
Author: '.$row['author'].'
</div>
</div>
<div class="row">
<div class="col-xl-2 col-lg-2 col-sm-3 col-3">
<h6>Question:</h6>
</div>
<div class="col-xl-9 col-lg-9 col-sm-9 col-9">
<textarea readonly style="width: inherit;">'.$row['question'].'</textarea>
</div>
</div>
<div class="row justify-content-between">
<div class="col-xl-2 col-lg-2 col-sm-4 col-5">
Subject name: '.$row['subjectID'].'
</div>
<div class="col-5">
Date: '.$row['date'].'
</div>
</div>
<div class="row" style="margin-top: 2%">
<div class="col-md-12 text-center">
<form action="" method="POST">
<button class="btn btn-success" type="submit" name="answers_question">Answer Question</button>
</form>
</div>
</div>
<hr>
</div>';
}
}

Answer 1

Given the question data is in the database I suggest using the query string $_GET for this (this also means your user can always navigate to an old question from their browser history).
To do this, you'd get rid of that form (that isn't really doing anything) and replace it with a link <a href="/answer_question.php?question_id="' . $row['id'] . '" class="button"> (assuming your row has an id called id and your css .button makes the link look like you want).
Then in answer_questions.php you just need to do $id = $_GET['id']; and then plug that into your database so you can display the question and build a form to answer it.

Answer 2

The most simple way is to use $_GET parameters.
The idea is to have the page with questions like:
/questions.php
And the question page:
/question-info.php?id=1
If you use mod_rewrite it can be
/questions/
/questions/1.html
And for better urls you can use slugs than ids