Posted over 2 years ago. Visible to the public. External content.

ActiveRecord: How to use ActiveRecord standalone within a Ruby script

Re-creating a complex ActiveRecord scenario quickly without setting up a full-blown Rails app can come in handy e.g. when trying to replicate a presumed bug in ActiveRecord with a small script.

# Based on # Run this script with `$ ruby my_script.rb` require 'sqlite3' require 'active_record' # Use `binding.pry` anywhere in this script for easy debugging require 'pry' # Connect to an in-memory sqlite3 database ActiveRecord::Base.establish_connection( adapter: 'sqlite3', database: ':memory:' ) # Define a minimal database schema ActiveRecord::Schema.define do create_table :shows, force: true do |t| t.string :name end create_table :episodes, force: true do |t| t.string :name t.belongs_to :show, index: true end end # Define the models class Show < ActiveRecord::Base has_many :episodes, inverse_of: :show end class Episode < ActiveRecord::Base belongs_to :show, inverse_of: :episodes, required: true end # Create a few records... show = Show.create!(name: 'Big Bang Theory') first_episode = show.episodes.create!(name: 'Pilot') second_episode = show.episodes.create!(name: 'The Big Bran Hypothesis') episode_names = show.episodes.pluck(:name) puts "#{} has #{show.episodes.size} episodes named #{episode_names.join(', ')}." # => Big Bang Theory has 2 episodes named Pilot, The Big Bran Hypothesis. # Use `binding.pry` here to experiment with this setup.

Does your version of Ruby on Rails still receive security updates?
Rails LTS provides security patches for old versions of Ruby on Rails (3.2 and 2.3).

Author of this card:

Thomas Klemm
Last edit:
over 2 years ago
by Arne Hartherz
About this deck:
We are makandra and do test-driven, agile Ruby on Rails software development.
License for source code
Posted by Thomas Klemm to makandropedia