如何在php应用程序中正确使用pdo？

I would know what is better for an application using pdo in php on the result and application speed.

  $Qcountries = $OSCOM_PDO->prepare('select countries_id,
                                        countries_name 
                                        from :table_countries
                                        where countries_iso_code_2 = :countries_iso_code_2 
                                        limit 1');
          $Qcountries->bindValue(':countries_iso_code_2', $country );
          $Qcountries->execute();

          $countries = $Qcountries->fetch();

          $country_name = $countries['countries_name'];

          echo $country_name;

or

  $Qcountries = $OSCOM_PDO->prepare('select countries_id,
                                        countries_name 
                                        from :table_countries
                                        where countries_iso_code_2 = :countries_iso_code_2 
                                        limit 1');
          $Qcountries->bindValue(':countries_iso_code_2', $country );
          $Qcountries->execute();

          echo $Qcountries->value('countries_name');