So, a friend of mine and I are tagging up to learn a little with php and mysql. Php is coming along swimmingly, but the mysql is a bit of a challenge right now. Part of what we're working on now is ...

I'm working on a web app, and it part of it, there is a very simple database-driven file/document manager. As a file manager, there is the possibility of sub-folders. So in the DB, I have the ...