Re-structuring data for Hierarchical Queries – or (Tree) Walking With Big Macs

Steve McNulty. Even the name sounds a bit hard. This is not the hero in Jason Statham’s latest celluloid exploit. Neither is it the central character in a hard-bitten cop drama.
Steve McNulty is, in fact the current Luton Town captain and a member of an endangered species – the stopper Centre-Half.
When you first set eyes on him, he looks, well, a bit chunky. You might imagine his nickname to be “Big Mac” because of his penchant for a certain fast-food chain.
This is something of a mis-conception.
Firstly, he’s not overweight. In contrast to the other players on the pitch, his body has not so much been honed to athletic perfection as hewn from solid rock.
It is a build that has not been seen for years in the elite (effete ?) Premier League.
He’s not the fastest player, as you’d expect, but he’s strong in the tackle. When he heads the ball, adjectives such as cushioning and glancing do not apply. It’s a Kirby Kiss (he’s a Scouser). The ball is definitely not his friend.
So, Big Mac he is not. He couldn’t be associated with anything that’s served with namby-pamby french-fries. A McNulty burger is a huge slab of meat wedged between two halves of a cottage loaf. It would only ever be served with chunky chips.
It’s McNulty and friends that provide the inspiration for the examples that follow.
I recently came across a situation where I needed to take some relational data and convert it into a hierarchy for the purposes of dropping it into an APEX tree. This proved slightly more challenging than I originally thought. Continue reading