How to create a form that uses data from multiple lines? - php

Question

First of all, I'm aware that the title is not very clear, it's because I'm having trouble put the issue I have into words, so if anyone understands what I'm about to describe, please suggest a new title for me to edit.
Now for the main problem, I will do my best to explain it :
The user ( a teacher ) logs in, he then chooses one of the classes he teaches, the website displays a list of the students that are in that class as a table.
the table contains 3 columns : Name , lastName, Present.
Present is a column containing 2 radio buttons : Absent & Present.
I want the teacher to choose one of them for every student, then press "Submit".
The submit will result in the insertion of data into a table that contains the ID of the student that was absent, the current date, and the ID of the class. Here is the code for showing the table :
<?php if (isset($_GET['choice'])) {
$choice = $_GET['choice'];
$showquery = $conn->prepare('select Nom,Prenom,etudiant_ID from etudiant where classe_id = (select classe_id from classe where abreviation= ?)');
$showquery->execute(array($choice));
echo $choice;
echo ("<form>");
echo "<table border='1'>
<tr>
<th>Nom</th>
<th>Prenom</th>
<th> Presence</th>
</tr>";
while ($row = $showquery -> fetch(PDO::FETCH_ASSOC)) {
$counter = $row['etudiant_ID'];
echo "<tr>";
echo "<td>" . $row['Nom'] . "</td>";
echo "<td>" . $row['Prenom'] . "</td>"; ?>
<td> Present <input type="radio" name="presence<?=$counter?>" value='present' checked>
Absent <input type="radio" name="presence<?=$counter?>" value="absent">
</td>
<?php
echo "</tr>";
}
echo "</table>";
echo ("<input name='matiere' placeholder='matiere..' required > ");
echo ("<form>");
} ?>
</main>
Here is an image that could help you better understand :
The table that is inside the form