Jifty::Upgrade - Superclass for schema/data upgrades to Jifty applications

  package MyApp::Upgrade;

  use base qw/ Jifty::Upgrade /;
  use Jifty::Upgrade qw/ since rename /;

  since '0.7.4' => sub {
      # Rename a column
      rename table => 'cthulus', name => 'description', 
                                   to => 'mind_numbingly_horrible_word_picture';
  };

  since '0.6.1' => sub {
      my @sizes       = ('Huge', 'Gigantic', 'Monstrous', 'Really Big');
      my @appearances = ('Horrible', 'Disgusting', 'Frightening', 'Evil');

      # populate new columns with some random stuff
      my $cthulus = MyApp::Model::CthuluCollection->new;
      while (my $cthulu = $cthulus->next) {
          $cthulu->set_size($sizes[ int(rand(@sizes)) ]);
          $cthulu->set_appearance($appearances[ int(rand(@appearances)) ]);
      }
  };

Jifty::Upgrade is an abstract base class to use to customize schema and data upgrades that happen.

since is meant to be called by subclasses of Jifty::Upgrade. Calling it signifies that SUB should be run when upgrading to version VERSION, after tables and columns are added, but before tables and columns are removed. If multiple subroutines are given for the same version, they are run in order that they were set up.

Returns the list of versions that have been registered; this is called by the Jifty::Script::Schema tool to determine what to do while upgrading.

Runs the subroutine that has been registered for the given version; if no subroutine was registered, returns a no-op subroutine.

Used in upgrade subroutines, this executes the necessary SQL to rename the table, or column in the table, to a new name.

Jifty::Manual::Upgrading