What is that for?
Extends ActiveRecord by adding pluck_to_hash
method that returns array of hashes instead of array of arrays. Useful when plucking multiple columns for rendering json or you need to access individual fields in your view for example.
Supports pluck_to_struct
since version 0.3.0. pluck_to_struct
returns an array of struct
s.
Installation
Add this line to your application's Gemfile:
gem 'pluck_to_hash'
And then execute:
$ bundle
Or install it yourself as:
$ gem install pluck_to_hash
Usage
Usage is similar to ActiveRecord.pluck
, for example
Post.limit(2).pluck_to_hash(:id, :title)
#
# [{:id=>213, :title=>"foo"}, {:id=>214, :title=>"bar"}]
#
Post.limit(2).pluck_to_hash(:id)
#
# [{:id=>213}, {:id=>214}]
#
Or use the shorter alias pluck_h
Post.limit(2).pluck_h(:id)
#
# [{:id=>213}, {:id=>214}]
#
Supports select
alias
User.pluck_to_hash(:id, 'created_at::date as my_date', 'created_at::time as my_time')
#
# [{:id=>23, :my_date=>Fri, 11 Jul 2014, :my_time=>2000-01-01 07:54:36 UTC},
# {:id=>2, :my_date=>Tue, 01 Jul 2014, :my_time=>2000-01-01 14:36:15 UTC}]
#
Accepts block
parameter
User.pluck_to_hash(:id, :title) do |user_hash|
...
end
Allows specifying the type of hash. Defaults to HashWithIndifferentAccess
User.pluck_to_hash(:id, :title, hash_type: CustomHash) do |custom_hash|
...
end
Using pluck_to_struct
posts = Post.limit(2).pluck_to_struct(:id, :title)
#
# [#<struct id=1, title="foo">, #<struct id=2, title="bar">]
#
posts.first.id
# 1
posts.first.title
# "foo"
or use the shorter alias pluck_s
posts = Post.limit(2).pluck_s(:id, :title)
#
# [#<struct id=1, title="foo">, #<struct id=2, title="bar">]
#
Supports block
parameter as well
Post.limit(2).pluck_to_struct(:id, :title) do |post_struct|
puts post_struct.title
end
Allows specifying the type of struct. Defaults to standard Struct.
Post.limit(2).pluck_to_struct(:id, :title, struct_type: OtherStructType) do |post_struct|
puts post_struct.title
end
Using with Sinatra or other non-rails frameworks without ActiveSupport
Use version 0.1.4
that removes ActiveSupport dependency. HashWithIndifferentAccess
is not used in that case.
Why not ActiveRecord.select
or ActiveRecord.as_json
?
Here are results of "benchmark" tests performed on MacBook Air. Each method did 10 runs, rejected the 2 highest and 2 lowest times and average the remaining 6. Ran these tests on about 40,000 records. We notice that pluck_to_hash
is almost 4x faster than select
and about 8x faster than as_json
. As with all the "benchmarks", you should take these results with a pinch of salt!
# Node.pluck_h(:id, :title)
# Node.select(:id, :title).to_a
# Node.select(:id, :title).as_json
user system total real
pluck_to_hash 0.145000 0.005000 0.150000 ( 0.164836)
select 0.566667 0.010000 0.576667 ( 0.590911)
as_json 1.196667 0.010000 1.206667 ( 1.222286)
Contributing
- Fork it ( https://github.com/girishso/pluck_to_hash/fork )
- Create your feature branch (
git checkout -b my-new-feature
) - Commit your changes (
git commit -am 'Add some feature'
) - Push to the branch (
git push origin my-new-feature
) - Create a new Pull Request
Licence
MIT License
Brought to you by: Cube Root Software © 2016