One of the many benefits of Rails is database independence. Migrations are particularly nice in this regard; and the easy-to-read / Rubyified display of your schema (via rake db:schema:dump) in schema.rb is icing on the cake.
But what about data? For import and export of the actual data, we’re stuck with mysqldump (or pg_dump, if you’re so inclined). Further, these dump formats are not terribly readable, contain lots of information you may or may not want to copy (like permissions, schema settings, views, triggers…you know, database features that Rails users are supposed to avoid).
Worst of all, ddata dumps are vendor specific, so you can’t move data between...