Doctrine2 QueryBuilder选择实体和关联实体的计数

use Doctrine\ORM\EntityManagerInterface;
use Doctrine\ORM\Query\Expr\Join;

// 获取EntityManager
$entityManager = // 从容器中获取EntityManager

// 创建QueryBuilder
$queryBuilder = $entityManager->createQueryBuilder();

// 选择实体和关联实体的计数
$queryBuilder->select('COUNT(entity.id) AS entityCount')
    ->addSelect('COUNT(relatedEntity.id) AS relatedEntityCount')
    ->from(Entity::class, 'entity')
    ->leftJoin('entity.relatedEntity', 'relatedEntity');

// 执行查询
$result = $queryBuilder->getQuery()->getResult();

// 获取计数结果
$entityCount = $result[0]['entityCount'];
$relatedEntityCount = $result[0]['relatedEntityCount'];