GraphQL::QueryResolver is an add-on to graphql-ruby that allows your field resolvers to minimize N+1 SELECTS issued by ActiveRecord.

GraphQL::QueryResolver will analyze the AST from incoming GraphQL queries and try to match query selections to ActiveRecord::Reflections present in your ActiveRecord models.

Every matched selection will be then passed on to ActiveRecord::Associations::Preloader.new so your queries now only issue one SELECT statement for every level of the GraphQL AST.

Add this line to your application's Gemfile:

gem 'graphql-query-resolver'

And then execute:

$ bundle

Or install it yourself as:

$ gem install graphql-query-resolver

require 'graphql/query_resolver'

# In your field resolver
# Assuming `Project < ActiveRecord::Base` and a `ProjectType` GraphQL type:
#
field :projects do
  type types[ProjectType]

  resolve -> (obj, args, ctx) {
    # Wrap your field resolve operation with `GraphQL::QueryResolver`
    GraphQL::QueryResolver.run(Project, ctx, ProjectType) do
      Project.all
    end
  }
end

# QueryResolver works the same way for single objects

field :comment do
  type CommentType
  argument :id, !types.ID

  resolve -> (obj, args, ctx) {
    GraphQL::QueryResolver.run(Comment, ctx, CommentType) do
      Comment.find(args['id'])
    end
  }
end

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.

Bug reports and pull requests are welcome on GitHub at https://github.com/nettofarah/graphql-query-resolver. 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.

To run the specs across all supported versions of ActiveRecord, check out the repo and follow these steps:

$ bundle install
$ bundle exec appraisal install
$ bundle exec appraisal rake

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