public function addAction(Request $request)
{
    $user = $this->get('security.token_storage')->getToken()->getUser();
    $em = $this->getDoctrine()->getManager();
    $post = new Post();
    $form = $this->createForm(PostType::class, $post);
    $form->handleRequest($request);
    if ($form->isValid()) {
        $sn = random_int(1000000, 9999999);
        $post->setSn($sn);
        $post->setCreator($user);
        $em->persist($post);
        $em->flush();
        return $this->redirectToRoute('_user_post');
    }
    return $this->render('frontend/user/post/form/post-add.html.twig', array(
        'form' => $form->createView()
    ));
}

request.CRITICAL: Uncaught PHP Exception DoctrineDBALExceptionNotNullConstraintViolationException: "An exception occurred while executing 'UPDATE dzb_user SET password = ? WHERE id = ?' with params [null, 1]:  SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'password' cannot be null" at /****/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php line 112 {"exception":"[object] (Doctrine\DBAL\Exception\NotNullConstraintViolationException(code: 0): An exception occurred while executing 'UPDATE dzb_user SET password = ? WHERE id = ?' with params [null, 1]:nnSQLSTATE[23000]: Integrity constraint violation: 1048 Column 'password' cannot be null at /****/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/AbstractMySQLDriver.php:112, Doctrine\DBAL\Driver\PDOException(code: 23000): SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'password' cannot be null at /home/antcto/public_html/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOStatement.php:93, PDOException(code: 23000): SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'password' cannot be null at /****/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOStatement.php:91)"} []