Many times people complain about movie adaptation ruining the book. Occasionally, however, the movie is better than the book.
This is one of those times.
Essentially the only similarity between the book and the movie is the characters' names, so you could consider the book to be a separate story altogether. However, it has nothing worthwhile to make it stand on its own. There is very little characterization and almost no character arcing, and there is very little moral or emotional depth to the narrative. The plot is sketchy, and the narrative is dry, impersonal, and makes odd use of all caps. To top it off, it's fairly heavily smeared with crude humor (including nudity). Overall, nothing truly memorable or enjoyable about this book. I'll stick with the film, personally.