Update Contact Information in PHP/MySQL Using PDO

<?php
include('db.php');
$result = $conn->prepare("SELECT * FROM tbl_member where tbl_member_id='$ID'");
$result->execute();
for($i=0; $row = $result->fetch(); $i++){
$id=$row['tbl_member_id'];
?>
 
<form method="post" action="edit_person_query.php<?php echo '?tbl_member_id='.$id; ?>">
<table border="1" cellspacing="5" cellpadding="5" width="100%">
	<tr>
		<td>
			<label>First Name</label>
		</td>
		<td width="395px">
			<input type="text" class="text_Box" name="first_name" value="<?php echo $row['first_name']; ?>" autofocus="autofocus" placeholder="First Name ....."  />
		</td>
	</tr>
	<tr>
		<td>
			<label>Last Name</label>
		</td>
		<td width="395px">
			<input type="text" class="text_Box" name="last_name" value="<?php echo $row['last_name']; ?>" placeholder="Last Name ....."  />
		</td>
	</tr>
	<tr>
		<td>
			<label>Contact Number</label>
		</td>
		<td width="395px">
			<input type="text" class="text_Box" name="contact_number" value="<?php echo $row['contact_number']; ?>" placeholder="Contact Number ....."  />
		</td>
	</tr>
	<tr>
		<td>
			<label>Email</label>
		</td>
		<td width="395px">
			<input type="email" class="text_Box" name="email" value="<?php echo $row['email']; ?>" placeholder="Email .....">
		</td>
	</tr>
	<tr>
		<td>
			<label>Address</label>
		</td>
		<td width="395px">
			<input type="text" class="text_Box" name="address" value="<?php echo $row['address']; ?>" placeholder="Address ....."  />
		</td>
	</tr>
	<tr>
		<td colspan="2">
			<a>
				<button type="submit" class="btn_confirm">
					Save Data
				</button>
			</a>
		</td>
	</tr>
</table>
</form>
<?php } ?>

<?php
include 'db.php';
 
$get_id=$_REQUEST['tbl_member_id'];
 
$first_name= $_POST['first_name'];
$last_name= $_POST['last_name'];
$contact_number= $_POST['contact_number'];
$email= $_POST['email'];
$address= $_POST['address'];
 
$sql = "UPDATE tbl_member SET first_name ='$first_name', last_name ='$last_name', 
contact_number ='$contact_number', email ='$email', address ='$address' WHERE tbl_member_id = '$get_id' ";
 
$conn->exec($sql);
echo "<script>alert('Successfully Edit The Account!'); window.location='index.php'</script>";
?>