Sinatra, MySQL and ActiveRecord

Question

how do I set up a simple sinatra app to use MySQL and ActiveRecord? I found some solutions, but none of them worked (maybe they are outdated):

http://ericfarkas.com/post

Answer 1

This is a dead simple Sinatra-MySQL-ActiveRecord application. It has 2 files:

Gemfile and app.rb

Gemfile:

source :rubygems
gem 'sinatra', '1.3.1'
gem 'activerecord', '3.2.13'

app.rb

require 'rubygems'
require 'sinatra'
require 'active_record'

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

class User < ActiveRecord::Base
end

ActiveRecord::Migration.create_table :users do |t|
  t.string :name
end

class App < Sinatra::Application
end

get '/' do
  p User.all
end

1. Create these 2 files
2. do bundle install (gem install bundler if you havent)
3. ruby app.rb

You should read how to insert data using ActiveRecord. In this case, you can manually enter some data to the table from MySQL and see the output.