ActiveRecord Starter Kit

.rubocop.yml

Metrics/LineLength:
  Max: 120

AllCops:
  TargetRubyVersion: 2.5
  Exclude:
    - 'db/schema.rb'
    - 'db/migrate/*'

README.md

mkdir -p db/migrate app/models config

bin-console

#!/usr/bin/env ruby
# frozen_string_literal: true

require 'irb'
require 'active_record'

Dir[File.join(__dir__, '..', '/app/**/*.rb')].each { |file| require file }

def reload!
  Dir[File.join(__dir__, '..', '/app/**/*.rb')].each { |file| load file }
end

db_config = YAML.safe_load(File.open('config/database.yml'))
ActiveRecord::Base.establish_connection(db_config)

binding.irb

db-config.yml

host: localhost
adapter: postgresql
encoding: utf-8
database: bg_library

Gemfile

# frozen_string_literal: true

source 'https://rubygems.org'

gem 'activerecord'
gem 'pg'

Rakefile

# frozen_string_literal: true

require 'active_record'

# rubocop:disable Metrics/BlockLength
namespace :db do
  db_config       = YAML.safe_load(File.open('config/database.yml'))
  db_config_admin = db_config.merge('database' => 'postgres', 'schema_search_path' => 'public')

  desc 'Create the database'
  task :create do
    ActiveRecord::Base.establish_connection(db_config_admin)
    ActiveRecord::Base.connection.create_database(db_config['database'])
    puts 'Database created.'
  end

  desc 'Migrate the database'
  task :migrate do
    ActiveRecord::Base.establish_connection(db_config)
    ActiveRecord::MigrationContext.new('db/migrate/').migrate
    Rake::Task['db:schema'].invoke
    puts 'Database migrated.'
  end

  desc 'Migrate the database'
  task :rollback do
    ActiveRecord::Base.establish_connection(db_config)
    ActiveRecord::MigrationContext.new('db/migrate/').rollback
    Rake::Task['db:schema'].invoke
    puts 'Last migration has been reverted.'
  end

  desc 'Drop the database'
  task :drop do
    ActiveRecord::Base.establish_connection(db_config_admin)
    ActiveRecord::Base.connection.drop_database(db_config['database'])
    puts 'Database deleted.'
  end

  desc 'Reset the database'
  task reset: %i[drop create migrate]

  desc 'Create a db/schema.rb file that is portable against any DB supported by AR'
  task :schema do
    ActiveRecord::Base.establish_connection(db_config)
    require 'active_record/schema_dumper'
    filename = 'db/schema.rb'
    File.open(filename, 'w:utf-8') do |file|
      ActiveRecord::SchemaDumper.dump(ActiveRecord::Base.connection, file)
    end
  end
end
# rubocop:enable Metrics/BlockLength

namespace :g do
  desc 'Generate migration'
  task :migration do
    name = ARGV[1] || raise('Specify name: rake g:migration your_migration')
    timestamp = Time.now.strftime('%Y%m%d%H%M%S')
    path = File.expand_path("../db/migrate/#{timestamp}_#{name}.rb", __FILE__)
    migration_class = name.split('_').map(&:capitalize).join

    File.open(path, 'w') do |file|
      file.write <<~END_MIGRATION
        # frozen_string_literal: true

        class #{migration_class} < ActiveRecord::Migration[5.2]
          def up; end

          def down; end
        end
      END_MIGRATION
    end

    puts "Migration #{path} created"
    abort # needed stop other tasks
  end
end