The adapter is mysql2. It’s specified in two places: the Gemfile and the front part of the DATABASE_URL. In a non-heroku rails app the two places will be the Gemfile and config/database.yml. The mysql2 adapter is used in the Rails Guide and should be used over mysql unless there are issues getting it to work. The mysql gem is still supported.
I saw the example URL on Xeround’s website and came up with my own, which uses an enhanced driver (mysql2). The Xeround one might work if you put mysql in your Gemfile instead of mysql2 but I wouldn’t recommend it.
I understand the rationale behind both connection strings (short and sweet) and yml files (super easy to grok). I prefer yml files, myself. I searched for a script to convert between them and didn’t find one. I personally would like to see one. :)
Thanks, and please let me know if you’ve got it working!