There is something called 'case expressions' in MS SQL queries...

This article is a bit outdated (http://www.craigsmullins.com/ssu_0899.htm) but it still makes a lot of sense. Jump to the "A more...

I was thinking you could do it by joining the table to itself. But then you have the problem of not knowing if the page you're looking up is in the 3rd or 4th level of 'childhood'.

Anyway, this is...