discourse/db/migrate/20191217035630_populate_topic_id_on_bookmarks.rb

# frozen_string_literal: true

class PopulateTopicIdOnBookmarks < ActiveRecord::Migration[6.0]
  def up
    Bookmark
      .where(topic_id: nil)
      .includes(:post)
      .find_each { |bookmark| bookmark.update_column(:topic_id, bookmark.post.topic_id) }
  end

  def down
    raise ActiveRecord::IrreversibleMigration
  end
end