I was having a lot of trouble with that using Oracle…what most of my current customers use, and decided to use OUT paramaters instead, to make life easier. There are, I'm sure, several dozen other methods at getting at these values, including third party adapters like TopXML. I would suggest trying to add the Out param IF you have some control over the SQL code and there aren't too many fields to return.
I haven't tested too many other ways, so maybe someone else had the answer you're looking for, but I'll keep my eyes open as well.
Of course, you can always access the table directly or use a view if that's an option.