symfony7通过DBAL查询数据:

通过connection, 其实是实现自: use Doctrine\DBAL\Connection; // 可以在控制器下或service 下手动引入
使用:
use Doctrine\DBAL\Connection;
  
public function __construct(
        private readonly EntityManagerInterface $em,
        private readonly Connection $connection,
    ) {
    }
  
public function test(){
  $data = $this->connection->fetchAllAssociative('SELECT * FROM events');
  $user = $this->connection->fetchAssociative(
      'SELECT * FROM mdpipub.users ORDER BY id ASC LIMIT 1'
  );
}
  
但是在迁移文件下，会自动继承 use Doctrine\Migrations\AbstractMigration; 里面默认有了connection实例
  
public function up(Schema $schema): void
{
    // this up() migration is auto-generated, please modify it to your needs
    foreach ($this->connection->fetchAllAssociative('SELECT * FROM events') as $event) {
        $this->addSql('INSERT INTO ticket_sections (id, title, `order`, is_special, event_id, created_at, updated_at, created_user_id) VALUES (NULL, "Other tickets", 0, 1, :eventId, :createdAt, :updatedAt, 3555803)', [
            'eventId'   => $event['id'],
            'createdAt' => (new \DateTime())->format('Y-m-d H:i:s'),
            'updatedAt' => (new \DateTime())->format('Y-m-d H:i:s'),
        ]);
    }
}