I like how interpreted languages provide this interpreter for you to try out stuff. As I am learning ruby on rails I frequently need to try out ActiveRecord's dark ways of doing things and I would like to be able to try it out in irb so here is what I do
and then execute the following code assuming you are in the rails app directory
After thins you can try out your model methods in the prompt.
This works with MySQL and should work with sqllite3 without any problems