While loop finding the last iteration only - php

Question

*How to solve this..??
My while loop is finding the last iteration only, If I select last attendance A then all the student's values will be 0, if I select P then all the values will be 1. So, how can I solve this?*
Index.php file
<?php
include'connection.php';
$sql = "SELECT * FROM `student_info`";
$result = mysqli_query($conn,$sql);
?>
<table border="1">
<tr>
<th>Student ID</th>
<th>First Name</th>
<th>Last Name</th>
<th>Attendance</th>
</tr>
<?php
while($row=mysqli_fetch_assoc($result))
{
$id = $row['stu_id'];
?>
<tr>
<td><?php echo $row['stu_id'];?></td>
<td><?php echo $row['first_name'];?></td>
<td><?php echo $row['last_name'];?></td>
<td>
<form action="attendance.php" method="post">
<select name="atten" id="">
<option value="1">P</option>
<option value="0">A</option>
</select>
</td>
</tr>
<?php
}
?>
</table>
<br>
<button type="submit">Submit</button>
</form>
attendance.php
<?php
include'connection.php';
$sql = "SELECT * FROM `student_info`";
$result = mysqli_query($conn,$sql);
while($row = mysqli_fetch_assoc($result))
{
if(isset($_POST['atten'])){
$atten = $_POST['atten'];
echo $atten.'<br>';
}
}
Here is output
Image for Index.php file
Image for attendance.php file

Answer 1

You're not submitting the student ID in the form. You can use a hidden input for this.
<?php
while($row=mysqli_fetch_assoc($result))
{
$id = $row['stu_id'];
?>
<tr>
<td><?php echo $row['stu_id'];?></td>
<td><?php echo $row['first_name'];?></td>
<td><?php echo $row['last_name'];?></td>
<td>
<form action="attendance.php" method="post">
<input name="stu_id" type="hidden" value="<?php echo $row['stu_id'];?>">
<select name="atten" id="">
<option value="1">P</option>
<option value="0">A</option>
</select>
</form>
</td>
</tr>
<?php
}
?>
Then in attendance.php you can update that student.
<?php
include'connection.php';
$stmt = $conn->prepare("UPDATE `student_info` set atten = ? WHERE stu_id = ?");
$stmt->bind_param("ii", $_POST['atten'], $_POST['stu_id']);
$stmt->execute();
echo "Attendance for student {$_POST['stu_id']} updated";