Question

I am doing a search in a collection for a document based on its id.

What is returned if find(the_id) can not be found?

session[:remote_ip] =  request.env['REMOTE_ADDR'].split(',').first
user = User.find({user_id: session[:remote_ip]})
if user.nil?
  # Do stuff if find couldn't find the user_id
  # Am I right to assume it will return nil?

Answer 1

Absolutely !

As you can see there is even a spec for it :

https://github.com/jnunemaker/mongomapper/blob/master/test/functional/test_querying.rb#L183

Give a try to Mongoid too.

This is another great gem for MongoDB :
https://github.com/mongoid/mongoid