How to use SQLite3?

[Shadowraix]

Alright, so I've started learning how SQLite3 works. I've been doing decent so far. I've got my table created and im already doing other stuff with it. One thing confuses me about the DB:exec() function that the documentation on the Lua SQLite3 page doesn't cover. What is udata? What does it represent as a parameter in the callback function?
Also, the third parameter to the exec() function I have no idea what its for and I assume its related to udata.

EDIT: I'm stupid, haha. udata is the third argument. "UserData" its to pass needed data into the callback I suppose.