PluckEach

ActiveRecord comes with find_each and find_in_batches to batch process records from a database. ActiveRecord also has the method pluck which allows the selection of a single field without pulling the entire record into memory.

This gem combines these ideas and provides pluck_each and pluck_in_batches to allow batch processing of plucked fields from the db.

  #
  # User.create(:first_name => "name1")
  # User.create(:first_name => "name2")
  # User.create(:first_name => "name3")
  # User.create(:first_name => "name4")
  # User.create(:first_name => "name5")
  #

User.all.pluck(:first_name) # => ["name1", "name2", "name3", "name4", "name5"]

# If the table is large you would want to "page" over these values
User.all.pluck_each(:first_name, :batch_size => 2) do |first_name| # default batch_size is 1000
  # do something with first_name
end

Installation

Add this line to your application's Gemfile:

gem 'pluck_each'

And then execute:

$ bundle

Or install it yourself as:

$ gem install pluck_each

Contributing

1. Fork it ( https://github.com/[my-github-username]/pluck_each/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request