PDO usage

$db = new PDO(
    'mysql:dbname=' . $cfg['DB']['database'] . ';host=' . $cfg['DB']['host'],
    $cfg['DB']['username'], $cfg['DB']['password']
);

$categories = [];
$stmt = $db->query('SELECT uid, title, parent FROM sys_category WHERE deleted = 0');
foreach ($stmt as $row) {
    if (isset($categories[$row['title']])) {
        die("Double title\n");
    }
    $categories[$row['title']] = $row['uid'];
}