Rails migration to create a Postgresql function that stripts every accent and outputs the string as lowercase, as seen in http://stackoverflow.com/questions/9243322/postgres-accent-insensitive-like-search-in-rails-3-1-on-heroku

20140428223544_add_lower_unaccent_function_to_db.rb

# -*- encoding : utf-8 -*-
class AddLowerUnaccentFunctionToDb < ActiveRecord::Migration
  def self.up
    execute "CREATE OR REPLACE FUNCTION lower_unaccent(character varying)
      RETURNS text
      AS $$
      SELECT lower(translate($1
           , '¹²³áàâãäåāăąÀÁÂÃÄÅĀĂĄÆćčç©ĆČÇĐÐèéêёëēĕėęěÈÊËЁĒĔĖĘĚ€ğĞıìíîïìĩīĭÌÍÎÏЇÌĨĪĬłŁńňñŃŇÑòóôõöōŏőøÒÓÔÕÖŌŎŐØŒř®ŘšşșߊŞȘùúûüũūŭůÙÚÛÜŨŪŬŮýÿÝŸžżźŽŻŹ'
           , '123aaaaaaaaaaaaaaaaaaacccccccddeeeeeeeeeeeeeeeeeeeeggiiiiiiiiiiiiiiiiiillnnnnnnooooooooooooooooooorrrsssssssuuuuuuuuuuuuuuuuyyyyzzzzzz'
           ));
      $$ IMMUTABLE STRICT LANGUAGE SQL;"
  end
  def self.down
    execute "drop function lower_unaccent(text) cascade"
  end
end