rails3 bigint primary key

Question

I would like to create a bigint (or string or whatever that is not int) typed primary key field under Rails 3.

I have a given

Answer 1

For MySQL you can use "SERIAL" which is alias for "BIGINT UNSIGNED NOT NULL AUTO_INCREMENT"

class ChangeUserIdToBigint < ActiveRecord::Migration
  def change
    change_column :users, :id, 'SERIAL'
  end
end