Symfony EntityType 使用

use Symfony\Bridge\Doctrine\Form\Type\EntityType;
$builder->add('users', EntityType::class, array(
    // 查询的 Entity，显示 username 字段
    'class' => 'AppBundle:User',
    'choice_label' => 'username',
));

use Doctrine\ORM\EntityRepository;
use Symfony\Bridge\Doctrine\Form\Type\EntityType;
$builder->add('users', EntityType::class, array(
    'class' => 'AppBundle:User',
    'query_builder' => function (EntityRepository $er) {
        return $er->createQueryBuilder('u')
            ->orderBy('u.username', 'ASC');
    },
    'choice_label' => 'username',
));

use Symfony\Bridge\Doctrine\Form\Type\EntityType;
$builder->add('category', EntityType::class, array(
    'class' => 'AppBundle:Category',
    'choice_label' => function ($category) {
        return $category->getDisplayName();
    }
));