Pluck multiple columns/attributes in Rails 3, 4, 5, 6, and can return data as hash instead of only array. Also supports Mongoid.
This Gem stands on the shoulders of this article: Plucking Multiple Columns in Rails 3. And modified to support not only Rail 3.
If you have a Rails 3 project, and want to pluck not only one column, feel free to use this gem and no need to worry about upgrading to Rails 4, 5, 6 in the future will break this.
- Ruby 2.3 ~ 2.7, 3.0 ~ 3.2
- Rails 3.2, 4.2, 5.0, 5.1, 5.2, 6.0, 6.1, 7.0, 7.1, 7.2
Add this line to your application's Gemfile:
gem 'pluck_all'And then execute:
$ bundle
Or install it yourself as:
$ gem install pluck_all
Behaves the same as #pluck method, but you can use it to pluck multiple columns in Rails 3
User.where('id < 3').pluck_array(:id, :account)
# => [[1, 'account1'], [2, 'account2']]Similar to #pluck method, but return array of hashes instead.
User.where('id < 3').pluck_all(:id, :account)
# => [{"id"=>1, "account"=>"account1"}, {"id"=>2, "account"=>"account2"}]
User.where('id < 3').pluck_all(:id, 'account AS name')
# => [{"id"=>1, "name"=>"account1"}, {"id"=>2, "name"=>"account2"}]
User.where('id < 3').pluck_all('id, account AS name')
# => [{"id"=>1, "name"=>"account1"}, {"id"=>2, "name"=>"account2"}]class User
include Mongoid::Document
field :name, type: String
field :age, type: Integer
end
User.pluck_all(:name, :age)
# => [
# {'name' => 'Pearl Shi' , 'age' => 18},
# {'name' => 'Rumble Huang', 'age' => 20},
# {'name' => 'Khiav Reoy' , 'age' => 20},
# ]pluck_all return raw hash data without loading a bunch of records, in that having better performace than using map and as_json. The following is the benchmark test on 191,093 users, where users table have 51 columns.
user system total real
map 36.110000 61.200000 97.310000 ( 99.535375)
select + map 10.530000 0.660000 11.190000 ( 12.550974)
select + as_json 49.040000 1.120000 50.160000 ( 55.417534)
pluck_all 3.310000 0.100000 3.410000 ( 3.527775)Test by benchmark-ips and limit 100 in each iteration:
Warming up --------------------------------------
map 1.000 i/100ms
select + map 28.000 i/100ms
select + as_json 7.000 i/100ms
pluck_all 54.000 i/100ms
Calculating -------------------------------------
map 14.230 (± 0.0%) i/s - 72.000 in 5.065349s
select + map 281.638 (± 4.6%) i/s - 1.428k in 5.081216s
select + as_json 73.241 (± 4.1%) i/s - 371.000 in 5.076235s
pluck_all 539.057 (± 6.7%) i/s - 2.700k in 5.034858s
Comparison:
pluck_all: 539.1 i/s
select + map: 281.6 i/s - 1.91x slower
select + as_json: 73.2 i/s - 7.36x slower
map: 14.2 i/s - 37.88x slower
Compare with pluck_to_hash gem
pluck_all has better performace since it uses raw hash data from ActiveRecord::Base.connection.select_all, while pluck_to_hash uses pluck method, which calls ActiveRecord::Base.connection.select_all and transfers the raw hash data to array format, and then transfer the data to hash format again. The following benchmark shows the performance difference:
user system total real
pluck_to_hash 2.960000 0.130000 3.090000 ( 3.421640)
pluck_all 2.160000 0.120000 2.280000 ( 2.605118)Tested by benchmark-ips and limit 1000 in each iteration:
Warming up --------------------------------------
pluck_to_hash 7.000 i/100ms
pluck_all 9.000 i/100ms
Calculating -------------------------------------
pluck_to_hash 84.526 (± 4.7%) i/s - 427.000 in 5.065792s
pluck_all 95.133 (± 4.2%) i/s - 477.000 in 5.021555s
Comparison:
pluck_all: 95.1 i/s
pluck_to_hash: 84.5 i/s - 1.13x slower
See the test script for more details.
class Post < ActiveRecord::Base
translates :title
endI18n.locale = :en
Post.pluck_all(:title)
# => [{ 'title' => 'english' }, { 'title' => 'english' }, ...]
I18n.locale = :'zh-TW'
Post.pluck_all(:title)
# => [{ 'title' => '中文' }, { 'title' => '中文' }, ...]User.where(xxx).pluck_all(:profile_pic).map{|s| s['profile_pic'] }is the same as
User.where(xxx).map(&:profile_pic)If the uploader use something like: model.id, model.name
You may have to send these columns manually:
User.where(xxx).cast_need_columns(%i[id name]).pluck_all(:id, :name, :profile_pic).map{|s| s['profile_pic'] }After checking out the repo, run bin/setup to install dependencies. Then, run rake test_active_record or rake test_mongoid 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/khiav223577/pluck_all. 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.