A bare-bones "just getting started" sinatra+sequel script

config.ru

#!/usr/bin/env rackup

# this sets up Bundler and has it require all the gems you mention in your Gemfile.
# neat!
require 'bundler'

# I've never investigated what these individually are doing, save that you can have
# different dev and production gemsets. I never do, but I keep the code the way it
# is.
Bundler.setup   :default, ENV['RACK_ENV'].to_sym
Bundler.require :default, ENV['RACK_ENV'].to_sym

# change the load path to include the current dir, as ruby 1.9 stripped that out
$LOAD_PATH.unshift File.expand_path('.', File.dirname(__FILE__))

# load our primary web application
require 'app'

# run the application
run Sinatra::Application

example.rb

# NB: these are now taken care of by config.ru
# require 'sinatra'
# require 'sequel'

DB = Sequel.connect(ENV['DATABASE_URL'])

get '/' do
    "Hello, world!"
end

get '/some_db_stuff' do
    # SELECT * FROM "accounts" WHERE "admin" IS TRUE LIMIT 1;
    account = DB[:accounts].filter do
        {:admin => true}
    end.first

    "The account name is #{account[:name]}"
end

__END__

The environment variable DATABASE_URL should be formatted like a URL:

    postgres://username:[email protected]:port/dbname

You'll want to make a table named accounts with some data:

    CREATE TABLE accounts (id SERIAL PRIMARY KEY, name TEXT NOT NULL, admin BOOLEAN NOT NULL DEFAULT FALSE);
    INSERT INTO accounts (name, admin) VALUES
        ('steve',  FALSE),
        ('matt',   TRUE),
        ('justin', FALSE);

To start this server:

    DATABASE_URL="url_from_earlier" rackup

`rackup` starts whatever rack server you're using by default on port 9292, so navigate to the following URLs while the server is running:

    http://localhost:9292/
    http://localhost:9292/some_db_stuff

Gemfile

source :rubygems

gem 'sinatra'
gem 'sequel'
gem 'pg'