Auto reverting Migrations

I often end up writing some code in self.up that craps out and it is painful to reverse any database changes that may have been committed. I often resort to revert to an earlier version, but that is an extra step I would rather not have to do.

I make sure all the extra code is located after any database changes I want to make and then wrap the whole shebang in a begin-rescue block:

class FixCategoriesOrder < ActiveRecord::Migration
  def self.up
    begin
      add_column :categories, :sort_order, :integer
      # ... other database changes

      # Code 
      [["Immunology", 1],
        ["Biochemistry", 2],
        ["Biotechnology", 3],
        ["Cell Biology", 4],
        ["Genomics", 5],
        ["Plant Biology", 6],
        ["Developmental Biology", 7],
        ["Ecology", 8],
        ["Other", 100]].each do |ar|
        puts "Processing #{ar[0]} - #{ar[1]}"
        Category.find_by_name(ar[0]).update_attribute(:sort_order, ar[1])
      end
    rescue
      self.down
      raise $!
    end

  end

  def self.down
    remove_column :categories, :sort_order
  end
end

Njoy