Stmt->errorCode not working - php

Question

im having a little problem getting the if($stmt->errorCode() == 0) { in my code to work. If i do a search with a ticket number that is in the database it will show it but if i do a search with a random number that's not in the database it will not show the error message no ticket found.
<?php
require("db.php");
$error_message="";
if (isset($_POST['submit'])){
if(empty($_POST['term']))
{
$error_message="Please enter a Ticket Number.";
}
else
{
$query = "SELECT department, subject, message FROM supporttickets Where ticketnumber LIKE :term";
$stmt = $db->prepare($query);
$stmt->execute(array(':term' => $_POST['term']));
if($stmt->errorCode() == 0) {
while (list($department,$subject,$message) = $stmt->fetch(PDO::FETCH_NUM)) {
echo htmlentities($department);
}
}else{
$error_message="no ticket found.";
}
}
}
?>

Answer 1

Your problem is that you're not actually echoing the output. This just assigns a variable:
$error_message="no ticket found.";
What you want is:
$error_message="no ticket found.";
echo $error_message;
Or maybe just:
echo "no ticket found.";

Answer 2

You don't need no error codes here
<?php
require("db.php");
$data = array();
if(!empty($_GET['term']))
{
$query = "SELECT department, subject, message FROM supporttickets
WHERE ticketnumber = ?";
$stmt = $db->prepare($query);
$stmt->execute(array($_GET['term']));
$data = $stmt->fetchAll();
}
foreach ($data as $row)
{
echo htmlspecialchars($row['department']);
}
if (!$data)
{
echo "Please enter valid Ticket Number.";
}
A couple of mistakes also corrected.