<?php
$db = new pdo('sqlite::memory:');
$db->beginTransaction();
$db->query('CREATE TABLE IF NOT EXISTS foobar (id INT AUTO INCREMENT, name TEXT)');
$db->commit();
$db->beginTransaction();
$db->query('INSERT INTO foobar VALUES (NULL, "PHP")');
$db->query('INSERT INTO foobar VALUES (NULL, "PHP6")');
$db->rollback();
$r = $db->query('SELECT COUNT(*) FROM foobar');
var_dump($r->rowCount());
$db->query('DROP TABLE foobar');