Chat::incrementMessageCount

public function incrementMessageCount(int $increment = 1): self
{
	$this->setMessageCount($this->getMessageCount() + $increment);

	if ($this->getChatId())
	{
		ChatTable::update($this->getChatId(), [
			'MESSAGE_COUNT' => new MainDBSqlExpression('?# + ' . $increment, 'MESSAGE_COUNT'),
			'LAST_MESSAGE_ID' => $this->getLastMessageId(),
		]);
	}

	return $this;
}