class DeleteNicknameInitUname < ActiveRecord::Migration def self.up remove_column :users, :nickname add_index :users, :uname, :unique => true User.all.each {|u| User.where(:id => u.id).update_all(:uname => u.email.split('@').first.gsub(/[^a-zA-Z0-9_]/, '_'))} end def self.down add_column :users, :nickname, :string remove_index :users, :uname User.all.each {|u| User.where(:id => u.id).update_all(:nickname => u.email.split('@').first.gsub(/[^a-zA-Z0-9_]/, '_'))} end end