Alternative for mysql_num_rows using PDO

$res = $DB->query('SELECT COUNT(*) FROM table');
$num_rows = $res->fetchColumn();

or

$res = $DB->prepare('SELECT COUNT(*) FROM table');
$res->execute();
$num_rows = $res->fetchColumn();

You can use this to ask if data exists or is selected, too:

$res = $DB->query('SELECT COUNT(*) FROM table');
$data_exists = ($res->fetchColumn() > 0) ? true : false;

Or with your variables:

$res = $DB->query('SELECT COUNT(*) FROM table');
$message = ($res->fetchColumn() > 0) ? array('status' => 'ok') : array('status' => 'error');

$stmt = $db->query('SELECT * FROM table');  
$row_count = $stmt->rowCount();  
echo $row_count.' rows selected';

Maybe you can use PDO's "fetchAll" method, which returns an array containing all the SELECT results. Then use "count" method to count the array's rows.

Ex:

$rows = $stmt->fetchAll();
$num_rows = count($rows);

If you are not using prepared statements then try:

$find = $dbh->query('SELECT count(*) from table');
if ($find->fetchColumn() > 0){
    echo 'found';
}

However, if you choose prepared statements, which i highly recommend, then:

$find = $dbh->prepare('SELECT count(*) from table');
$find->execute();
if ($find->fetchColumn() > 0){
    echo 'found';
}