$user = new User(); // new record
$user = Doctrine_Manager::getInstance()->getTable('User')->find(1); // existing record
 
$user['username'] = 'username';
$user->username = 'username';
$user->setUsername('username');
$user->set('username', 'username');
 
echo $user['username']; // username
echo $user->username; // username
echo $user->getUsername(); // username
echo $user->get('username'); // username