BaseReport::getTotalCountByColumnName

public function getTotalCountByColumnName(string $columnName): int
{
	$totalDataQuery =
		$this
			->getQuery()
			->setLimit(null)
			->setOffset(null)
	;

	$entity = Entity::getInstanceByQuery($totalDataQuery);
	$totalCountQuery = new Query($entity);

	return
		$totalCountQuery
			->setSelect([
				'CNT' => Query::expr()->count($columnName)
			])
			->exec()
			->fetch()['CNT']
		;
}