Data Operations

Similar to JPA/Hibernate, Symfony Doctrine bundle provides basic CRUD operations and flexible criteria builder to create complex queries.

ObjectManager and ObjectRepository

In Doctrine common package, there are two core components available for data persistence purpose.

• ObjectManager is the interface mainly provided for the end user that used to find, persist, update and delete objects.
• ObjectRepository is used to retrieve instances by more flexible queries.

Doctrine ORM provides derived class of ObjectManager - EntityManagerInerface and its implementation class. It also provides a subclass of ObjectRepository - EntityRepository.

Doctrine also includes a Doctrine ODM package for MongoDB, it uses the same interfaces from the Common package to perform data operations.

Symfony integrates Doctrine tightly and makes these components work in its service container.

• There is a EntityManagerInterface in the service container , you can inject it in any injectable components, such as Controller, Command, etc.
• Symfony adds an extra EntityServiceRepository which extends from EntityRepository. All the generated repositories by make bundle are derived from the EntityServiceRepository class. It allows you to access the service container in your own Repository.
• In your own Repository, you can create complex queries by QueryBuilder API.

The ObjectManager and ObjectRepository provide interoperating methods.

• There is a ObjectManager.getRepository method to locate the specific Repository that targets the Entity argument.
• And there is getEntityManager method available in your own Repository to retrieve the instance of EntityManagerInterface.

Creating Command

To demonstrate the usage of EntityManagerInterfce , we will generate a command firstly, then inject EntityManagerInterfce via constructor to insert sample data into database.

Run the following command to generate a Command from the built-in templates.

$ php bin/console make:command add-post

It will generate a AddPostCommand under src/Command folder.

Change it as expected.

#[AsCommand(
    name: 'app:add-post',
    description: 'Add a short description for your command',
)]
class AddPostCommand extends Command
{


    public function __construct(private EntityManagerInterface $manager)
    {
        parent::__construct();
    }

    protected function configure(): void
    {
        $this
            ->addArgument('title', InputArgument::REQUIRED, 'Title of a post')
            ->addArgument('content', InputArgument::REQUIRED, 'Content of a post')
            //->addOption('option1', null, InputOption::VALUE_NONE, 'Option description')
        ;
    }

    protected function execute(InputInterface $input, OutputInterface $output): int
    {
        $io = new SymfonyStyle($input, $output);
        $title = $input->getArgument('title');

        if ($title) {
            $io->note(sprintf('Title: %s', $title));
        }

        $content = $input->getArgument('content');

        if ($content) {
            $io->note(sprintf('Content: %s', $content));
        }

        $entity = PostFactory::create($title, $content);
        $this ->manager->persist($entity);
        $this ->manager->flush();

//        if ($input->getOption('option1')) {
//            // ...
//        }

        $io->success('Post is saved: '.$entity);

        return Command::SUCCESS;
    }
}

The Doctrine EntityManagerInterface is managed by Symfony Service Container. The persist method is used to persist entities, and flush to commit the transaction.

To test if it work as expected, run the following command to execute the newly created add-post command.

# php bin/console app:add-post "test title" "test content"
 ! [NOTE] Title: test title                                               
 ! [NOTE] Content: test content                                                             
 [OK] Post is saved: Post: [ id =1ec3d3ec-895d-685a-b712-955865f6c134, title=test title, content=test content, createdAt=1636010040, blishedAt=] 

As you see, it is exectued successfully. It will add a new Post into database.