StatisticsLastUpdated.php

<?php

namespace Drupal\comment\Plugin\views\sort;

use Drupal\views\Plugin\views\sort\Date;

/**
 * Sort handler for the newer of last comment / entity updated.
 *
 * @ingroup views_sort_handlers
 *
 * @ViewsSort("comment_ces_last_updated")
 */
class StatisticsLastUpdated extends Date {
  public function query() {
    $this->ensureMyTable();
    $this->node_table = $this->query
      ->ensureTable('node', $this->relationship);
    $this->field_alias = $this->query
      ->addOrderBy(NULL, "GREATEST(" . $this->node_table . ".changed, " . $this->tableAlias . ".last_comment_timestamp)", $this->options['order'], $this->tableAlias . '_' . $this->field);
  }

}