Activerecord without rails example

activerecord.rb

require 'mysql2'
require 'active_record'

ActiveRecord::Base.establish_connection(
    :adapter => "mysql2",
    :host => "localhost",
    :username => "username",
    :password => "password",
    :database => "garage")

class Car < ActiveRecord::Base
end

car = Car.new
car.name = "Tesla"
car.model = "Model X P100D 4x4"
car.max_speed = 250
car.engine = "Electro"

car.save

Gemfile

# frozen_string_literal: true

source "https://rubygems.org"

git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }

gem 'activerecord'
gem 'mysql2'