class AddBookmarkCountToPosts < ActiveRecord::Migration[4.2] def change add_column :posts, :bookmark_count, :integer, default: 0, null: false add_column :forum_threads, :bookmark_count, :integer, default: 0, null: false add_column :forum_threads, :star_count, :integer, default: 0, null: false execute "UPDATE posts SET bookmark_count = (SELECT COUNT(*) FROM bookmarks WHERE post_number = posts.post_number AND forum_thread_id = posts.forum_thread_id)" execute "UPDATE forum_threads SET bookmark_count = (SELECT COUNT(*) FROM bookmarks WHERE forum_thread_id = forum_threads.id)" execute "UPDATE forum_threads SET star_count = (SELECT COUNT(*) FROM forum_thread_users WHERE forum_thread_id = forum_threads.id AND starred = true)" end end