rosa-build/db/migrate/20111017152936_create_categories.rb

class CreateCategories < ActiveRecord::Migration
  def self.up
    create_table :categories do |t|
      t.string :name
      t.string :ancestry
      t.integer :projects_count, :default => 0, :null => false

      t.timestamps
    end
  end

  def self.down
    drop_table :categories
  end
end