Club Drupal

    $uid_is_set = FALSE;

        // Flag that an user ID is explicitly set. This will skip the

        // validations for existing user name and mail address defined below.

        $uid_is_set = TRUE;

        // Check if the given user ID already exists.

    // Look for other validation constraints.

    $errors = array();

    // Validate the user name.

    if ($error = user_validate_name($account->name)) {

      $errors[] = $error;

    }

    // Check for an existing user name, unless an user ID is explicitly set.

    if (!$uid_is_set && (bool) db_select('users')->fields('users', array('uid'))->condition('uid', $account->uid, '<>')->condition('name', db_like($account->name), 'LIKE')->range(0, 1)->execute()->fetchField()) {

      $errors[] = t("The name '@name' is already taken.", array('@name' => $account->name));

    }

    // Check for an existing mail address, unless an user ID is explicitly set.

    if (!$uid_is_set && (bool) db_select('users')->fields('users', array('uid'))->condition('uid', $account->uid, '<>')->condition('mail', db_like($account->mail), 'LIKE')->range(0, 1)->execute()->fetchField()) {

      $errors[] = t("The e-mail address '@email' is already taken.", array('@email' => $account->mail));

    }

      $errors[] = t("Failed importing '@name'. User's timezone is not valid.", array('@name' => $account->name));

    }

    if (!empty($errors)) {

      throw new FeedsValidationException(implode("\n", $errors));