Does rake db:migrate only add new migrations, or does it drop all migrations/changes and build everything new? I think rake is throwing an error because it is trying to access a table attribute in migration 040 that was deleted in migration 042. somehow my DB and rake are out of synch and I want to fix them. for you experts out there - is it common for rake to get out of synch with migrations? how can I avoid this (no, I do not hand-edit my schema or rake files).