class UserStorage

class UserStorage extends SqlContentEntityStorage implements UserStorageInterface {

  /**
   * {@inheritdoc}
   */
  protected function doSaveFieldItems(ContentEntityInterface $entity, array $names = []) {

    // The anonymous user account is saved with the fixed user ID of 0. MySQL
    // does not support inserting an ID of 0 into serial field unless the SQL
    // mode is set to NO_AUTO_VALUE_ON_ZERO.
    // @todo https://drupal.org/i/3222123 implement a generic fix for all entity
    //   types.
    if ($entity
      ->id() === 0) {
      $database = \Drupal::database();
      if ($database
        ->databaseType() === 'mysql') {
        $sql_mode = $database
          ->query("SELECT @@sql_mode;")
          ->fetchField();
        $database
          ->query("SET sql_mode = '{$sql_mode},NO_AUTO_VALUE_ON_ZERO'");
      }
    }
    parent::doSaveFieldItems($entity, $names);

    // Reset the SQL mode if we've changed it.
    if (isset($sql_mode, $database)) {
      $database
        ->query("SET sql_mode = '{$sql_mode}'");
    }
  }

  /**
   * {@inheritdoc}
   */
  public function updateLastLoginTimestamp(UserInterface $account) {
    $this->database
      ->update($this
      ->getDataTable())
      ->fields([
      'login' => $account
        ->getLastLoginTime(),
    ])
      ->condition('uid', $account
      ->id())
      ->execute();

    // Ensure that the entity cache is cleared.
    $this
      ->resetCache([
      $account
        ->id(),
    ]);
  }

  /**
   * {@inheritdoc}
   */
  public function updateLastAccessTimestamp(AccountInterface $account, $timestamp) {
    $this->database
      ->update($this
      ->getDataTable())
      ->fields([
      'access' => $timestamp,
    ])
      ->condition('uid', $account
      ->id())
      ->execute();

    // Ensure that the entity cache is cleared.
    $this
      ->resetCache([
      $account
        ->id(),
    ]);
  }

  /**
   * {@inheritdoc}
   */
  public function deleteRoleReferences(array $rids) {

    // Remove the role from all users.
    $this->database
      ->delete('user__roles')
      ->condition('roles_target_id', $rids, 'IN')
      ->execute();
    $this
      ->resetCache();
  }

}