gistfile1.txt

<?php

$pdo = new PDO('mysql:unix_socket=/var/run/mysqld/mysqld.sock;dbname=test', 'root', '');
$pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
/*
$pdo->exec('
CREATE PROCEDURE out_bug(OUT param INT UNSIGNED)
BEGIN
    SET param := 3;
END;
');
*/

$out = 0;
$s = $pdo->prepare('CALL out_bug(:out)');
$s->bindParam('out', $out, PDO::PARAM_INT, 0);
$s->execute();
echo 'out is: ' . $out . "\n";