public function applyLimitOffset($sql, $limit = -1, $offset = -1)
{
$limit = $limit !== null ? (int) $limit : -1;
$offset = $offset !== null ? (int) $offset : -1;
$limitStr = $limit >= 0 ? ' LIMIT ' . $limit : '';
$offsetStr = $offset >= 0 ? ' OFFSET ' . $offset : '';
return $sql . $limitStr . $offsetStr;
}