Repository::deleteOldMessages

public function deleteOldMessages($folderCurrentName)
{
	$connection = MainApplication::getInstance()->getConnection();
	$sqlHelper = $connection->getSqlHelper();
	$sql = 'DELETE from ' . MailMailMessageUidTable::getTableName() .
		' WHERE MAILBOX_ID = ' . intval($this->mailboxId) .
		" AND DIR_MD5 = '" . $sqlHelper->forSql(md5($folderCurrentName)) . "'" .
		' AND MSG_UID = 0;';
	$connection->query($sql);
	return $connection->getAffectedRowsCount();
}