There is a new rake task for redoing a migration:
BTW, if you need to do it on a production server, then just append RAILS_ENV:
rake db:migrate:redo RAILS_ENV=production
and of course, if you want to list all rake tasks:
Migrating to Rails 2.0 and mass-assignment warning
I was upgrading one application from Rails 1.2.3 to Rails 2.0. The application uses restful_authentication. One of the problems we have seen, was a warning in the log, saying something like 'mass-assignment no longer supported'. After investigation we found out that the problem was updating the user object. The User model was generated with restful_authentication, but later there were some application specific attributes added by a developer. Since restful_authentication generates a line like that:
it means other attributes are not accessible. Adding the new attributes to this list solves the problem.
atttr_accessible :email, :birthdate