how to login in magento admin using coding

UPDATE core_config_data
SET value = "http://www.example.com/"
WHERE path = "web/unsecure/base_url"
AND scope_id = 0;

UPDATE core_config_data
SET value = "https://www.example.com/"
WHERE path = "web/secure/base_url"
AND scope_id = 0;

    $cookieParams = array(
        'lifetime' => $cookie->getLifetime(),
        'path'     => $cookie->getPath()/*,
        'domain'   => $cookie->getConfigDomain(),
        'secure'   => $cookie->isSecure(),
        'httponly' => $cookie->getHttponly() */
    );