Episodes
David Kimura PRO said about 1 year ago on Friend Requests From Scratch :
  if you've not deployed the application yet then you can roll back the database migrations first and then make the changes. If you have already deployed the application then things get a bit trickier because you've already gotten data populated on those columns. If you've already deployed the application or have team mates and the code has already been merged then I would create another migration.