I made a graphql controller that resolves information about category’s from doctrine-orm. The problem starts when I input following command to my terminal:

curl -X POST http://localhost:8000/graphql   -H "Content-Type: application/json"   -d '{"query": "{ category(id: 1) { category_id category_name } }"}'

Category class

    <?php
namespace AppModels;

use AppEntityTechCategory;
use AppEntityClothCategory;
use DoctrineORMMapping as ORM;
use DoctrineCommonCollectionsArrayCollection;
use DoctrineCommonCollectionsCollection;


#[ORMEntity]
#[ORMTable(name: 'category')]
#[ORMInheritanceType("SINGLE_TABLE")]
#[ORMDiscriminatorColumn(name: 'discr', type: 'string')]
#[ORMDiscriminatorMap(['tech' => TechCategory::class, 'cloth' => ClothCategory::class])]
class Category
{
    #[ORMId]
    #[ORMColumn(type: 'integer')]
    #[ORMGeneratedValue]
    protected $category_id;

    #[ORMColumn(type: 'string')]
    protected $category_name;

    //There can be many products to a single category
    #[ORMOneToMany(targetEntity: "Product", mappedBy: "category")]
    protected Collection $products;

    public function __construct()
    {
        $this->products = new ArrayCollection();
    }

    // Getters and setters...

    public function getCategoryId(): int
    {
        return $this->category_id;
    }

    public function getCategory(): string
    {
        return $this->category_name;
    }

    public function setCategory(string $category_name): void
    {
        $this->category_name = $category_name;
    }

    public function getProducts(): Collection
    {
        return $this->products;
    }

    public function addProduct(Product $product): void
    {
        if (!$this->products->contains($product)) {
            $this->products[] = $product;
            $product->setCategory($this);
        }
    }

    public function removeProduct(Product $product): void
    {
        if ($this->products->contains($product)) {
            $this->products->removeElement($product);
            if ($product->getCategory() === $this) {
                $product->getCategory(null);
            }
        }
    }
}

Graphql Controller

<?php

namespace AppController;


use AppModelsCategory;
use GraphQLGraphQL as GraphQLBase;
use GraphQLTypeDefinitionObjectType;
use GraphQLTypeDefinitionType;
use GraphQLTypeSchema;
use GraphQLTypeSchemaConfig;
use RuntimeException;
use Throwable;
use DoctrineORMEntityManagerInterface;

class GraphQL {

    private $entityManager;

    public function __construct(EntityManagerInterface $entityManager)
    {
        $this->entityManager = $entityManager;
    }
   

    public function handle() {
        try {
            //Category: category_id, category_name, products 

            $categoryType = new ObjectType([
                'name' => 'Category',
                'fields' => [
                    'category_id' => Type::int(),
                    'category_name' => Type::string(),
                ]
            ]);
            
            $queryType = new ObjectType([
                'name' => 'Query',
                'fields' => [
                    'category' => [
                        'type' => $categoryType,
                        'args' => [
                            'id' => ['type' => Type::int()],
                        ],
                        'resolve' => function ($rootValue, array $args) {
                            $categoryId = $args['id'];
                            return $this->entityManager->getRepository(Category::class)->find($categoryId);
                        },
                    ],
                ],
            ]);

            $schema = new Schema(
                (new SchemaConfig())
                ->setQuery($queryType)
                // ->setMutation($mutationType)
            );
        
            $rawInput = file_get_contents('php://input');
            if ($rawInput === false) {
                throw new RuntimeException('Failed to get php://input');
            }
        
            $input = json_decode($rawInput, true);
            $query = $input['query'];
            $variableValues = $input['variables'] ?? null;
        
            // $rootValue = ['prefix' => 'You said: '];
            $result = GraphQLBase::executeQuery($schema, $query, null, null, $variableValues);
            $output = $result->toArray();
        } catch (Throwable $e) {
            $output = [
                'error' => [
                    'message' => $e->getMessage(),
                ],
            ];
        }

        header('Content-Type: application/json; charset=UTF-8');
        return json_encode($output);
    }
}

Index.php

<?php

require_once __DIR__ . '/../vendor/autoload.php';
require_once __DIR__ . '/../app/Config/bootstrap.php';
use FastRouteRouteCollector;
use FastRouteDispatcher;
use AppControllerGraphQL;
use DoctrineORMEntityManagerInterface;

$graphQLController = new GraphQL($entityManager);

$dispatcher = FastRoutesimpleDispatcher(function(FastRouteRouteCollector $r) use ($graphQLController) {
    $r->post('/graphql', [$graphQLController, 'handle']);
});

$routeInfo = $dispatcher->dispatch(
    $_SERVER['REQUEST_METHOD'],
    $_SERVER['REQUEST_URI']
);

switch ($routeInfo[0]) {
    case FastRouteDispatcher::NOT_FOUND:
        // ... 404 Not Found
        http_response_code(404);
        echo '404 Not Found';
        break;
    case FastRouteDispatcher::METHOD_NOT_ALLOWED:
        $allowedMethods = $routeInfo[1];
        // ... 405 Method Not Allowed
        http_response_code(405);
        echo '405 Method Not Allowed';
        break;
    case FastRouteDispatcher::FOUND:
        $handler = $routeInfo[1];
        $vars = $routeInfo[2];
        echo call_user_func($handler, $vars);
        break;
}

Output that I get when I run the curl command is

{"data":{"category":{"category_id":null,"category_name":null}}}

Thoughts

Doctrine is setup correctly I can list rows from mysql database trough entity manager however problems start when I try to query them out. I don’t know if it’s because there is products array in my category class or because there are sub classes to my category class.

Any help would be greatly appreciated!