google服务帐户示例返回“刷新OAuth2令牌时发生错误{"error":"invalid_grant"}“

我的目标是代表Web应用程序用户在Google Fusion Tables上进行最简单的查询.为此，我在Google控制台上创建了一个服务帐户.这是代码:

My goal is to make the simplest query on Google Fusion Tables on behalf of my web app users. For that, I created a service account on google console. Here is the code:

    // Creating a google client
    $client = new \Google_Client();


    // setting the service acount credentials
    $serviceAccountName = 'XXXXX.apps.googleusercontent.com';
    $scopes= array(
                'https://www.googleapis.com/auth/fusiontables',
                'https://www.googleapis.com/auth/fusiontables.readonly',
                );
    $privateKey=file_get_contents('/path/to/privatekey.p12');
    $privateKeyPassword='notasecret'; // the default one when generated in the console

    $credential = new \Google_Auth_AssertionCredentials($serviceAccountName,
            $scopes, $privateKey, $privateKeyPassword);

    // setting assertion credentials
    $client->setAssertionCredentials($credential);

    $service = new \Google_Service_Fusiontables($client);
    $sql = 'select name from XXXXXXXX'; 
    $result = $service->query->sql($sql);

运行此代码后，出现此错误:

After running this code, I got this error:

Error refreshing the OAuth2 token, message: '{
"error" : "invalid_grant"
}'

我用Google搜索了好几天，大多数答案都在谈论刷新令牌.我做了刷新，但仍然是相同的错误！

I googled that for days and most of answers are talking about refreshing the token. I made this refresh but still the same errors!

有解决这个问题的主意吗? 谢谢

Any idea for solving this problem? Thanks