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Comment utiliser ActiveRecord dans un script Ruby en dehors de Rails?

J'ai un petit script Ruby dans lequel j'aimerais utiliser ActiveRecord pour accéder facilement à un modèle de base de données. Quelle est la meilleure façon de le faire?

ruby-on-railsrubyactiverecordscripting
56
Daniel Cukier
require 'active_record'

# Change the following to reflect your database settings
ActiveRecord::Base.establish_connection(
  adapter:  'mysql2', # or 'postgresql' or 'sqlite3' or 'Oracle_enhanced'
  Host:     'localhost',
  database: 'your_database',
  username: 'your_username',
  password: 'your_password'
)

# Define your classes based on the database, as always
class SomeClass < ActiveRecord::Base
  #blah, blah, blah
end

# Now do stuff with it
puts SomeClass.find :all
some_class = SomeClass.new
89
Pesto

Il convient de noter que dans les versions ultérieures de activerecord (v3 +), vous devez l'exiger comme tel

require "active_record"
10
Andy Henson

Vous pouvez créer un script minimal avec une base de données SQLite en mémoire en quelques lignes seulement. Cette réponse est également disponible sous forme de Gist .

Inspiré par article de blog de Jon Leighton sur la façon de publier un rapport de bogue ActiveRecord impressionnant.

# 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.
8
Thomas Klemm