ActiveRecord scope methods for ordering by an explicit list of values.
Common use cases:
- Preserving search result ordering from external services (Elasticsearch, Algolia, etc.)
- Displaying records in user-defined order stored as an array of IDs
- Maintaining order after filtering a pre-ordered list of IDs
This gem adds two methods to active record scopes: .order_by_ids, and the more general .order_by.
Examples:
user1 = User.create(id: 1)
user2 = User.create(id: 2)
user3 = User.create(id: 3)
User.order_by_ids([2,3,1]) #=> [user2, user3, user1]user3 = User.create(parent_id: 3)
user2 = User.create(parent_id: 2)
user1 = User.create(parent_id: 1)
User.order_by(parent_id: [2,3,1]) #=> [user2, user3, user1]Multiple columns:
User.order_by(parent_id: [2, 1], study_id: %w[B A])- Records with values not in the list are sorted to the end
- NULL values are sorted to the end
- Works with non-integer values (strings, etc.)
- Chainable with other scopes:
User.where(active: true).order_by_ids([2, 3, 1]).limit(10)Tested with SQLite, PostgreSQL, and MySQL.
After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.
Bug reports and pull requests are welcome on GitHub at https://github.com/botandrose/active_record-order_by_ids.
The gem is available as open source under the terms of the MIT License.