Drag and Drop...trying to make it happen

[eluser]NateL[/eluser]
So the jQuery UI has nifty Drag and Drop functionality and I'm trying to figure out how to implement it into CodeIgniter.

My first i'm trying to wrap my head around is how that information is stored in a database.

Lets say we have 5 names, stored in this particular order in the database:

1. John
2. Julie
3. Bill
4. Eric
5. Fred


Using Drag and drop, we re-arrange those names into the order we want - John is position 1, Julie is position 2 - when they're swapped, what would be a good method for swapping the position number for each name?

Any tips to get me going in the right direction would be much appreciated.