PHP / MySQL代码在MySQL版本5.5.34的本地主机上运行，​​但在MySQL版本5.5.40-36的服务器上不能运行。 代码有什么问题？

I have this code that works on my localhost connecting to my Godaddy database, but when I put it up on the Godaddy server, it does not work. What needs to be changed to make it work? I know that the connection to the database works because I have another PHP file that retrieves items with no problem.

It connects to the DB, then tries to execute the following code:

try {


$dbh = new PDO($dns, $user, $pass);
$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

//$pdo = new PDO("mysql:host=$hostname;dbname=$database", $username, $password);

$items = [];

$start = isset($_GET['start']) ? (int)$_GET['start'] -1 : 0;
$count = isset($_GET['count']) ? (int)$_GET['count'] : 1;

$item = $dbh->query("SELECT SQL_CALC_FOUND_ROWS * FROM portfolio_items LIMIT $start, $count");
$itemsTotal = $dbh->query("SELECT FOUND_ROWS() AS count")->fetch(PDO::FETCH_ASSOC)['count'];

if($itemsCount = $item->rowCount()) {
    $items = $item->fetchAll(PDO::FETCH_OBJ);
}

echo json_encode(array(
    'items' => $items,
    'last' => ($start + $count) >= $itemsTotal ? true : false,
    'start' => $start,
    'count' => $count
    ));

}
catch (PDOException $e) {
    error_reporting(E_ALL);
}

?>