sending while loop radio button data to database using php - php

Question

The first two values of the radio are not being inserted, is there any problem with the condition in for loop?
I have the html code(form) and the php code on the bottom
<?php
$i=1;
$name=$data['username'];
$sql1 = "SELECT * from membre where groupe='$name'";
$run1 = mysqli_query($db,$sql1);
while($row = mysqli_fetch_assoc($run1)){
?>
<tr>
<td> <?php echo $i; $i++; ?></td>
<td style="display: none;" ><input value="<?php echo $i; ?>" name="id[]" class="form-control" readonly="readonly" > </td>
<td ><input value="<?= $row['nom']; ?>" name="nom1[]" class="form-control" readonly="readonly" > </td>
<td><input type="radio" name="presence[<?php echo $i; ?>]" value="Présent"></td>
<td><input type="radio" name="presence[<?php echo $i; ?>]" value="Absent"></td>
</tr>
<?php
}
?>
for($i=0; $i<$_POST['id'][$i]; $i++) {
$id = mysqli_real_escape_string($db,trim($_POST['id'][$i]));
$nom1= mysqli_real_escape_string($db,trim($_POST['nom1'][$i]));
$presence= mysqli_real_escape_string($db,trim($_POST['presence'][$i]));
$v1 = "INSERT INTO presence(rapport_id,groupe,dat,nom,presence) values('$rapport_id','$groupe','$dat','$nom1','$presence')";
$r = mysqli_query($db,$v1);

Answer 1

$i<$_POST['id'][$i] is not the correct looping condition. You should be using the length of $_POST['id'] as the loop limit.
Or just use foreach. And also use a prepared statement instead of substituting variables directly into the query.
$stmt = $db->prepare("INSERT INTO presence(rapport_id,groupe,dat,nom,presence) values(?, ?, ?, ?, ?)");
$stmt->bind_param("issss", $id, $groupe, $dat, $nom1, $presence);
foreach ($_POST['id'] as $i => $id) {
$nom1 = trim($_POST['nom1'][$i];
$presence = $_POST['presence'][$i];
$stmt->execute();
}
I assume $rapport_id in your code should be $id.