example_4.rb

class User < ActiveRecord::Base
  attr_accessible :email, :first_name, :last_name

  def self.name_matching(name)
    where("lower(first_name) LIKE lower(:name)
      OR lower(last_name) LIKE lower(:name)", name: name + "%")
  end

  def self.email_matching(email)
    where("lower(email) LIKE lower(?)", email + "%")
  end
end