Thanks for the link Jeff.
Bit beyond me at the moment though.
I failed the "Who This Article Is For" section.
Never heard of Adjacency List or Nested Sets.
If / when I get involved with hierarchies, I know who's name to google. :-)
For better, quicker answers on T-SQL questions, read Jeff Moden's suggestions.
"Million-to-one chances crop up nine times out of ten." ― Terry Pratchett, Mort