my QCubed PHP class "Project" has a property called "Finished" which is object of QDateTime and data type "datetime" in MySQL database. I need to save NULL into database when user leaves this field blank in HTML
<input type="datetime-local" name="Finished" />
but I cannot find a way for it since PHP always throws Internal Server Error 500
if ($_GET["Finished"] != "") $objProject->Finished = new QDateTime($_GET["Finished"]);
else $objProject->Finished = ???
Will be glad for any help.