pdo如何获取全部字段啊

$result = mysql_query("SELECT * FROM table");$fields = mysql_num_fields($result);for ($i=0; $i < $fields; $i++) {   $names[] = mysql_field_name($result, $i);}print_r($names);

try {  $dbh = new PDO('mysql:host=localhost;dbname=test', 'root', '');  $stmt = $dbh->query("select * from tbl_name");  for($i=0; $i<$stmt->columnCount(); $i++) {    echo $stmt->getColumnMeta($i)['name'], PHP_EOL;//php5.4适使用，之前的版本需拆成两句  }} catch (PDOException $e) {  die("Error!: " . $e->getMessage());}