Migrations after the fact ...

If you want to add a 'references' field to a table after the fact, see:

http://stackoverflow.com/questions/493777/addcolumn-for-references-rails

If you want to redo a specific migration:

rake db:migrate:redo VERISON=X

or you can redo specific operations.

rake db:migrate:up VERSION=X
rake db:migrate:down VERSION=X

Note that db:migrate:up didn't seem to work for me. I ended up adding a dummy table in the database and then running 'redo' and that seemed to work.

See. http://stackoverflow.com/questions/1316889/rails-run-specific-migration