I've tried to take a look to DataMapper with Rails 3, so I follow this simple instruction on http://github.com/datamapper/dm-rails.
$ rails new testing_dm3 -m http://datamapper.org/templates/rails.rb $ cd testing_dm3 $ bundle install $ rails g scaffold Person name:string $ rake db:setup /Users/jm/.rvm/gems/ruby-head@rails3dm/gems/rake-0.8.7/lib/rake/alt_system.rb:32: Use RbConfig instead of obsolete and deprecated Config. (in /Users/jm/dev/personal/testing_dm3) [datamapper] Created database 'testing_dm3_development.db' [datamapper] Created database 'testing_dm3_test.db' [datamapper] Finished auto_migrate! for :default repository 'testing_dm3_development.db'
$ thin start (I like thin)
Go to http://0.0.0.0:3000/people and you should see
DataObjects::SyntaxError in People#index no such table: people
If you don't, you are lucky. I fixed this modifying database.yml:
change "database" to "path" database: testing_dm3_development.db to path: ./db/testing_dm3_development.db
$ rake db:setup (again)
That fixed it for me. That happend because the database is in_memory and doesn't create the files, if you run the migration on a rails console, inside the console you can CRUD your objects, but when you left the session you lost the data.