thats one of the things I love about postgresql, you can wrap migrations in a transaction, so failed migrations leave the database in a determinable state. coupled with this plugin, it makes life easier...
http://www.redhillonrails.org/#transactional_migrations However (at least with cap 1) if the migration does fail on your production server during a cap deploy, I think you need to still manually do a revert of the migration using... > rake migrate VERSION=nnn on the server, then do a cap rollback, as cap won't do the migration rollback for you. On May 8, 6:33 am, Jamis Buck <[EMAIL PROTECTED]> wrote: > Migrations are tricky beasts, because if they fail halfway through, > your database will be left with part of the migration applied. Most > DBMS's will not allow you to do things like table creations or column > additions inside a transaction, so there is no easy way to atomically > apply a migration. Thus, Capistrano (by default) does not try to wrap > your migration inside a transaction. > > If things go sour, you can manually rollback: > > 1. Determine what parts of your migration succeeded, and manually > undo those changes in your database. > > 2. cap deploy:rollback_code (or, on cap1, just "cap rollback_code") > > It is strongly recommended that you thoroughly test your migrations > in your development and testing environments before you run them in > production. If possible, get a snapshot of your production data that > you can use in development to run them against. > > - Jamis > > On May 8, 2007, at 6:41 AM, dweinand wrote: > > > > > Hello, > > i'm just looking for a solution to rollback my app after a migration > > failed. > > > I'd like to run the migration with every deploy command. but if the > > migration fails, i'd like to rollback to the last version before the > > migration. > > > can i do a "dry run" to check if the migration is ok? or do i have to > > deploy the application, call the migration and if the migration fails > > rollback the whole thing? > > > how can i determine if the migration failed? just tried with an > > transaction but i think i missunderstand there something. > > > regards --~--~---------~--~----~------------~-------~--~----~ To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/capistrano -~----------~----~----~----~------~----~------~--~---
