doc/technical/archived_migrations/20171201095546_update_participant_challenges_to_version_3.rb
class UpdateParticipantChallengesToVersion3 < ActiveRecord::Migration[5.0]
def change
drop_table :challenge_registrations
create_view :challenge_registrations
update_view :participant_challenges, version: 3, revert_to_version: 2
end
end