How do i ping the MySQL db and reconnect using PDO

Question

I am using MySQL PDO for handling database querying and all. But most of the time, the MySQL connection is gone away. So i am looking in the PDO that will check if the db co

Answer 1

I tried to find a solution for the same problem and I found the next answer:

class NPDO {
    private $pdo;
    private $params;

    public function __construct() {
        $this->params = func_get_args();
        $this->init();
    }

    public function __call($name, array $args) {
        return call_user_func_array(array($this->pdo, $name), $args);
    }

    // The ping() will try to reconnect once if connection lost.
    public function ping() {
        try {
            $this->pdo->query('SELECT 1');
        } catch (PDOException $e) {
            $this->init();            // Don't catch exception here, so that re-connect fail will throw exception
        }

        return true;
    }

    private function init() {
        $class = new ReflectionClass('PDO');
        $this->pdo = $class->newInstanceArgs($this->params);
    }
}

Full story here: https://terenceyim.wordpress.com/2009/01/09/adding-ping-function-to-pdo/

Somebody else was thinking to use PDO::ATTR_CONNECTION_STATUS, but he figured out that: "$db->getAttribute(PDO::ATTR_CONNECTION_STATUS) keeps replying “Localhost via UNIX socket” even after stopping mysqld".

Answer 2

You can use like this:

# connect to the database
try {
  $DBH = new PDO("mysql:host=$host;dbname=$dbname", $user, $pass);
  $DBH->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );

}
catch(PDOException $e) {
    echo "Connection error " . $e->getMessage() . "\n";
    exit;
}