discourse/db/migrate/20140705081453_index_user_badges.rb

# frozen_string_literal: true

class IndexUserBadges < ActiveRecord::Migration[4.2]
  def change
    execute "DELETE FROM user_badges USING user_badges ub2
             WHERE  user_badges.badge_id = ub2.badge_id AND
                    user_badges.user_id = ub2.user_id AND
                    user_badges.post_id IS NOT NULL AND
                    user_badges.id < ub2.id
    "
    add_index :user_badges, %i[badge_id user_id post_id], unique: true, where: "post_id IS NOT NULL"
  end
end