Random data listing and grouping - php

Question

I have a 9-person classroom. I want to randomly divide the students in this class into three-person classes. It keeps returning the same names in my query. How can I do this, can you help?
I listed all the students first. Then I want to randomly group them into three.
My source code:
<?php
require 'db.php';
$students = $db->query('SELECT * FROM students')->fetchAll(PDO::FETCH_ASSOC);
?>
<div class="container mt-2">
<div>
<table class="table table-bordered">
<thead>
<tr>
<th scope="col">ID</th>
<th scope="col">Name</th>
<th scope="col">No</th>
</tr>
</thead>
<tbody>
<?php foreach($students as $student): ?>
<tr>
<th scope="row"><?php echo $student['id'] ?></th>
<td><?php echo $student['name'] ?></td>
<td><?php echo $student['no'] ?></td>
</tr>
<?php endforeach; ?>
</tbody>
</table>
</div>
<?php
$randomstudents = $db->query('select * from students order by rand() limit 3')->fetchAll(PDO::FETCH_ASSOC);
?>
<div class="row">
<div class="col-md-3">
<h6>3 Person Classroom</h6>
<hr>
<ul>
<?php foreach($randomstudents as $rs): ?>
<li><?php echo $rs['name']; ?></li>
<?php endforeach; ?>
</ul>
</div>
<div class="col-md-3 offset-md-1">
<h6>3 Person Classroom</h6>
<hr>
<?php foreach($randomstudents as $rs): ?>
<li><?php echo $rs['name']; ?></li>
<?php endforeach; ?>
</div>
<div class="col-md-3 offset-md-1">
<h6>3 Person Classroom</h6>
<hr>
<?php foreach($randomstudents as $rs): ?>
<li><?php echo $rs['name']; ?></li>
<?php endforeach; ?>
</div>
</div>
</div>

Answer 1

you can try to use array_chunk()
<?php
$randomstudents = $db->query('select * from students order by rand()')
->fetchAll(PDO::FETCH_ASSOC);
$randomstudents = array_chunk($randomstudents, 3);
foreach ($randomstudents as $groupOfThree) :
?>
<div class="col-md-3">
<h6>3 Person Classroom</h6>
<hr>
<ul>
<?php foreach($groupOfThree as $rs): ?>
<li><?php echo $rs['name']; ?></li>
<?php endforeach; ?>
</ul>
</div>
<?php endforeach; ?>