We can use ActiveRecord and Mongoid in one app. This Rails3 app is that sample.
Add 'bson_ext' and 'mongoid' to Gemfile, and run bundle
.
Then run rails g mongoid:config
to generate a configuration file for Mongoid.
After installing mongoid, 'model' generator is for Mongoid.
$ r g model todo_log title:string done:boolean invoke mongoid create app/models/todo_log.rb
So, when you're creating an ActiveRecord model file, use 'active_record:model' generator.
$ r g active_record:model todo title:string done:boolean create db/migrate/20110730071022_create_todos.rb create app/models/todo.rb