detached_counter_cache

detached_counter_cache is a tool for keeping track of a counter cache that lives in its own table. It works with Rails 4.1 and 4.2, and only MySQL.

For example, with User and Comment classes you may want to cache user.comments.size, but don't want to create comments_count on User.

class User < ActiveRecord::Base
  has_many :comments
end

class Comment < ActiveRecord::Base
  belongs_to :user, detached_counter_cache: true
end

You'll need to generate a migration that creates your counter cache table.

create_table :users_comments_counts, force: true do |t|
  t.integer :user_id, null: false
  t.integer :count, default: 0, null: false
end

• stopdropandrew
• drewchandler
• duncanbeevers

MIT License