Доступ к корневому значению и разрешению аргументов graphql-Stack Overflow

У меня проблемы со следующей частью моего кода с использованием graphql-php библиотеки.

'resolve' =>function($value,$args,$context)

Когда я запускаю запрос:

"http://localhost:8080/index.php?query={certificate(id:"123ecd"){id}}"

Я получаю приведенное ниже сообщение:

{"errors":[{"message":"Internal server error","category":"internal",
"locations":[{"line":1,"column":2}],"path":["certificate"]}],"data":{"certificate":null}}

Во-вторых, когда я запускаю вложенный запрос

"http://192.168.211.15:8080/index.php?query{certificates{id,products{id}}}"

Я получаю приведенный ниже ответ:

{"errors":[{"message":"Internal server error","category":"internal","locations":[{"line":1,"column":26}],"path":["certificates",0,"products"]}
"data":{"certificates":[{"id":"a023gavcx","status":"Valid","products":null}]}}

Ниже мой полный код:

  use GraphQL\Type\Definition\ObjectType;
use GraphQL\Type\Definition\ResolveInfo;
class CertificateType extends ObjectType{
public function __construct(){
$config = [
'name' => 'Certificate',
'fields' => function() {
return [
'id' => [
'type' => Types::nonNull(Types::string()),
],
'number' => [
'type' => Types::int()
],
'first_issue_date' => [
'type' => Types::string()
],
'products' => [
'type' => Types::product(),

'resolve'=> function($value, $args, $context){
$pdo = $context['pdo'];
$cert_id = $value->id;

$result = $pdo->query("select * from products where cert_id = {$cert_id} ");
return $result->fetchObject() ?: null;
}
]];
}

];
parent::__construct($config);
}

}use GraphQL\Type\Definition\Type;

class Types extends Type{

protected static $typeInstances = [];

public static function certificate(){
return static::getInstance(CertificateType::class);
}

public static function product(){
return static::getInstance(ProductType::class);
}

protected static function getInstance($class, $arg = null){
if (!isset(static::$typeInstances[$class])) {
$type = new $class($arg);
static::$typeInstances[$class] = $type;
}
return static::$typeInstances[$class];
}
}

use GraphQL\Type\Definition\ObjectType;
use GraphQL\Type\Definition\ResolveInfo;

class ProductType extends ObjectType
{
public function __construct()
{
$config = [
'name' => 'Product',
'fields' => function() {
return [
'id' => [
'type' => Types::nonNull(Types::string()),
],
'primary_activity' => [
'type' => Types::string()
],
'trade_name' => [
'type' => Types::string()
],
];
},
];
parent::__construct($config);
}

}require_once __DIR__ . '/../../../../autoload.php';
use GraphQL\GraphQL;
use GraphQL\Type\Schema;
use GraphQL\Type\Definition\ObjectType;
use GraphQL\Type\Definition\Type;

define('BASE_URL', 'http://127.0.0.1:8080');

ini_set('display_errors', 0);$debug = !empty($_GET['debug']);
if ($debug) {
$phpErrors = [];
set_error_handler(function($severity, $message, $file, $line) use (&$phpErrors) {
$phpErrors[] = new ErrorException($message, 0, $severity, $file, $line);
});
}
try {
$dbHost = 'localhost';
$dbName  = '*******';
$dbUsername = 'root';
$dbPassword = '*********';

$pdo = new PDO("mysql:host={$dbHost};dbname={$dbName}", $dbUsername, $dbPassword);
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$appContext = [
'pdo' => $pdo  ];

if (isset($_SERVER['CONTENT_TYPE']) && strpos($_SERVER['CONTENT_TYPE'], 'application/json') !== false) {
$raw = file_get_contents('php://input') ?: '';
$data = json_decode($raw, true);
} else {

$data = $_REQUEST;
}

$data += ['query' => null, 'variables' => null];

if (null === $data['query']) {

$data['query'] = '{hello}';
}
require __DIR__ . '/types/CertificateType.php';
require __DIR__ . '/types/ProductType.php';
require __DIR__ . '/types/OrganizationType.php';

require __DIR__ . '/Types.php';

$queryType = new ObjectType([
'name' => 'Query',
'fields' => [
'hello' => [
'description' => ' Hello world',
'type' => Types::string(),
'resolve' => function() {
return 'Hello World';
}
],
'certificate' => [
'type' => Types::listOf(Types::certificate()),
'description' => 'This is the certificate identification',
'args' => [
'id' => Types::string()],
'resolve' => function ($rootValue,$args,$context) {
$pdo = $context['pdo'];
$id = $args['id'];

return $pdo->query("SELECT * from certificates where  id ={$id}");
return $data->fetchObject() ?: null;
}
],
'certificates' => [
'type' => Types::listOf(Types::certificate()),
'resolve' => function($rootValue, $args, $context) {
$pdo = $context['pdo'];
$result = $pdo->query("select * from certificates  order by id  limit 10");
return $result->fetchAll(PDO::FETCH_OBJ);
}
],

]
]);

$schema = new Schema([
'query' => $queryType
]);

$result = GraphQL::execute(
$schema,
$data['query'],
null,
$appContext,
(array) $data['variables']
);

if ($debug && !empty($phpErrors)) {
$result['extensions']['phpErrors'] = array_map(
['GraphQL\Error\FormattedError', 'createFromPHPError'],
$phpErrors
);
}
$httpStatus = 200;
} catch (\Exception $error) {
//  Handling Exception
// *************************************
$httpStatus = 500;
if (!empty($_GET['debug'])) {
$result['extensions']['exception'] = FormattedError::createFromException($error);
} else {
$result['errors'] = [FormattedError::create('Unexpected Error')];
}
}

header('Content-Type: application/json', true, $httpStatus);
echo json_encode($result);

Может кто-нибудь помочь мне решить эти проблемы. заранее спасибо