Counter Cache for ActiveRecord

Add this line to your application's Gemfile:

gem 'counter_cache'

And then execute:

$ bundle

Or install it yourself as:

$ gem install counter_cache

For example models

Item model: models/item.rb

  class Item < ActiveRecord::Base
  
    belongs_to :list
    
    scope :published, -> { where(status: :published) }
  
  end

  belongs_to :list
  counter_cache :list

Or by ActiveRecord supported

  belongs_to :list, counter_cache: true

We will caching to items_count column in lists table

• By model scopes

  counter_cache :list, scope: :published

• By where hash

  counter_cache :list, scope: { status: :published }

• By where string

  counter_cache :list, scope: "status = 'published'"

• Set column name to caching

  counter_cache :list, column: :custom_name

Default column name to cached is append _count to self table name

=> items + _count

  counter_cache :list, scope: :published, column: :published_items_count

• Multiple caching

  counter_cache :list, scope: :published, column: :published_items_count
  counter_cache :list, scope: { status: :rejected }, column: :rejected_items_count

Bug reports and pull requests are welcome on GitHub at https://github.com/ThanhKhoaIT/counter_cache. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

The gem is available as open source under the terms of the MIT License.

Everyone interacting in the CounterCache project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.