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 http://www.jonathanleighton.com/articles/2011/awesome-active-record-bug-reports/
# 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 "#{show.name} 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.
Posted by Thomas Klemm to makandra dev (2015-04-27 21:04)