Cleanup invalid aspects and set unique index

class CleanupAspectsAndAddUniqueIndex < ActiveRecord::Migration[5.1]

  class Aspect < ApplicationRecord

  end

  def up

    cleanup_aspects

    add_index :aspects, %i[user_id name], name: :index_aspects_on_user_id_and_name, length: {name: 190}, unique: true

  end

  def down

    remove_index :aspects, name: :index_aspects_on_user_id_and_name

  end

  def cleanup_aspects

    Aspect.where(user_id: 0).delete_all

    Aspect.joins("INNER JOIN aspects as a2 ON aspects.user_id = a2.user_id AND aspects.name = a2.name")

          .where("aspects.id > a2.id").each do |aspect|

      aspect.update_attributes(name: "#{aspect.name}_#{UUID.generate(:compact)}")

    end

  end

end