This post originated from an RSS feed registered with Ruby Buzz by rwdaigle. Original Post: What's New in Edge Rails: UTC-based Migration Versioning Feed Title: Ryan's Scraps Feed URL: http://feeds.feedburner.com/RyansScraps Feed Description: Ryan Daigle's various technically inclined rants along w/ the "What's new in Edge Rails" series. Latest Ruby Buzz Posts Latest Ruby Buzz Posts by rwdaigle Latest Posts From Ryan's Scraps

Rails migrations are a somewhat contentious bunch. On one hand they provide a consistent way of provisioning your database, and on the other hand they like to conflict with each other if there’s a heavy stream of development due to a simplistic naming convention. Just in is a change that will name your migrations based on a more unique UTC-based timestamp instead of just a sequential ordering.

When you go to create your next migration you’ll see something like this:

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> script/generate migration one
      create  db/migrate/20080402122512_one.rb

Instead of the migration file being named 001_one.rb it now has a more unique prefix that will less likely conflict with another migration somebody else happened to check-in around the same time.

Another change that accompanies this functionality is the addition of rake db:migrate:up and rake db:migrate:down tasks, which will let you run the up and down operations of an individual migration (that may have been added on an svn merge or update):

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> rake db:migrate:up VERSION=20080402122523
== 20080402122523 Two: migrating ==============================================
-- create_table(:two)
   -> 0.0122s
== 20080402122523 Two: migrated (0.0124s) =====================================

This functionality was previously available as the enhanced migrations plugin, so if you’re on an older version of Rails you can still make your migrations less whiny.

tags: ruby, rubyonrails