Ruby开发：Sinatra+ActiveRecord+MySQL

如果担心Rails的ActionPack封装太厉害而影响性能，可以考虑使用更轻量的Sinatra.

以下代码展示如何使用Sinatra+ActiveRecord+MySQL：

require 'sinatra'
require 'active_record'
require 'mysql2'

#Connetction
ActiveRecord::Base.establish_connection(
adapter:  'mysql2',
host:     'localhost',
database: 'my_db',
username: 'root',
password: 'root'
)

#Model
class Account < ActiveRecord::Base
end

#Sinatra Route
get '/hi' do
puts Account.find :all
"Hello World!"
end

Ruby下另外几个web框架：

Sinatra：http://www.sinatrarb.com/intro-zh.html

Padrino：http://www.padrinorb.com/

Goliath：http://postrank-labs.github.io/goliath/