[Xenon]

depends on what you want.

faster should be the if-way (if it really works )
but nicer is the reapeated while.

if it wouldn't produce too much queries on an often called page, i'd use the while-method.
if it's an page where it's important of how much queries are on, i'd use the if method, but code it better readable in a half while or recursive method to get the querystring