post方法后PHP页面消失

当我用表单运行post方法时，我的PHP页面几乎是空白的。我想知道这是谷歌云平台的问题还是我将应用程序加载到谷歌云平台上的方式的问题。这是我的应用程序

runtime: php
env: flex
runtime_config:
document_root: .
handlers:
- url: /(.+.(html|png|jpg|js|css))$
static_files: 1
upload: .+.(html|png|jpg|js|css)$
- url: /.*
script: auto
entrypoint:
serve handler.php
env_variables:
CLOUDSQL_USER: root
CLOUDSQL_DB: COSGymPatronData
CLOUDSQL_PASSWORD: ************
CLOUDSQL_DSN: /cloudsql/cosgym:us-central1:cosgympatrondata

这是我的handler.php:

<?php
ini_set('allow_url_fopen',1);
switch(@parse_url($_SERVER['REQUEST_URI'])['path']) {
case '/':
require 'index.php';
case '/index':
require 'index.php';
case '/index.php':
require 'index.php';
case '/result_contact.php':
require 'result_contact.php';
case '/checkout.php':
require 'checkout.php';  
case '/loginAction.php': 
require 'loginAction.php';
case 'signinAction.php':
require 'signinAction.php';
}
?>

这是我的数据库.php页面：

<?php
function prepare_string($dbc, $string) {
$string = mysqli_real_escape_string($dbc, trim($string));
return $string;
}
define('DB_USER', get_env('CLOUDSQL_USER'));
define('DB_PASSWORD', get_env('CLOUDSQL_PASSWORD'));
define('DB_HOST', get_env('CLOUDSQL_DSN'));
define('DB_NAME', get_env('CLOUDSQL_DB'));
$dbc = @mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME)
OR die('Could not connect to MySQL: ' . mysqli_connect_error());
mysqli_set_charset($dbc, 'utf8');
?>

最后，这里有一个php的例子，它在上一个表单的操作页面上运行：

<?php
require 'database.php';
$errors=[];
if(!empty($_POST['name'])) {
$name = $_POST['name'];
} else {
$name = NULL;
$errors[] = "<p>We need your name </p>";
}

if(!empty($_POST['email'])) {
$email = $_POST['email'];
if(!filter_var($email, FILTER_VALIDATE_EMAIL)) {
$errors[] =  "<p>Your email is incorrect '$email' </p>";
$email = NULL;        
}
}else{
$errors[] =  "<p>We need your email </p>";
$email = NULL;        
}

if(!empty($_POST['subject'])) {
$subject = $_POST['subject'];
} else {
$subject = NULL;
$errors[] = "<p>We need your subject </p>";
}

if(!empty($_POST['message'])) {
$message = $_POST['message'];
} else {
$message = NULL;
$errors[] = "<p>We need your message </p>";
}
$name_clean = prepare_string($dbc, $name);
$email_clean = prepare_string($dbc, $email);
$subject_clean = prepare_string($dbc, $subject);
$message_clean = prepare_string($dbc, $message);
$q = "INSERT INTO Contact(name, email, subject, message) VALUES(?, ?, ?, ?)";
$stmt = mysqli_prepare($dbc, $q);
mysqli_stmt_bind_param(
$stmt,
'ssss',
$name_clean,
$email_clean,
$subject_clean,
$message_clean
);
$result = mysqli_stmt_execute($stmt);
if (!$result)
{
$errors[]="<p>Error Access DB</p>";
}
if(count($errors)==0) {
echo "<p>Welcome to COS GYM Our managers will contact you</p>";
}else
{
foreach($errors as $err) 
{
echo $err;
}
}
?>

我应该注意的是，我正在为CloudSQL和应用程序引擎上运行的内容收取免费积分，而且这些数据看起来像是进入了数据库，所以结果页面上的代码似乎正在工作。我们将不胜感激。