```ruby
require 'uri'
require 'time'
require 'sinatra/base'
require 'active_record'
require 'logger'

module Sinatra
  module ActiveRecordHelper
    def database
      options.database
    end
  end

  module ActiveRecordExtension
    def database=(url)
      @database = nil
      set :database_url, url
      database
    end

    def database
      @database ||= begin
        ActiveRecord::Base.logger = activerecord_logger
        ActiveRecord::Base.establish_connection(database_options)
        ActiveRecord::Base
      end
    end

  protected

    def database_options
      url = URI.parse(database_url)
      options = {
        :adapter => url.scheme,
        :host => url.host,
        :port => url.port,
        :database => url.path[1..-1],
        :username => url.user,
        :password => url.password
      }
      case url.scheme
      when "sqlite"
        options[:adapter] = "sqlite3"
        options[:database] = url.host
      when "postgres"
        options[:adapter] = "postgresql"
      end
      options.merge(database_extras)
    end

    def self.registered(app)
      app.set :database_url, lambda { ENV['DATABASE_URL'] || "sqlite://#{environment}.db" }
      app.set :database_extras, Hash.new
      app.set :activerecord_logger, Logger.new(STDOUT)
      app.database # force connection
      app.helpers ActiveRecordHelper

      app.before do
        # re-connect if database connection dropped
        ActiveRecord::Base.verify_active_connections!
      end
    end
  end

  register ActiveRecordExtension
end
```

Clear active connections after each request
user
```ruby
require 'uri'
require 'time'
require 'sinatra/base'
require 'active_record'
require 'logger'

module Sinatra
  module ActiveRecordHelper
    def database
      options.database
    end
  end

  module ActiveRecordExtension
    def database=(url)
      @database = nil
      set :database_url, url
      database
    end

    def database
      @database ||= begin
        ActiveRecord::Base.logger = activerecord_logger
        ActiveRecord::Base.establish_connection(database_options)
        ActiveRecord::Base
      end
    end

  protected

    def database_options
      url = URI.parse(database_url)
      options = {
        :adapter => url.scheme,
        :host => url.host,
        :port => url.port,
        :database => url.path[1..-1],
        :username => url.user,
        :password => url.password
      }
      case url.scheme
      when "sqlite"
        options[:adapter] = "sqlite3"
        options[:database] = url.host
      when "postgres"
        options[:adapter] = "postgresql"
      end
      options.merge(database_extras)
    end

    def self.registered(app)
      app.set :database_url, lambda { ENV['DATABASE_URL'] || "sqlite://#{environment}.db" }
      app.set :database_extras, Hash.new
      app.set :activerecord_logger, Logger.new(STDOUT)
      app.database # force connection
      app.helpers ActiveRecordHelper

      app.before do
        # re-connect if database connection dropped
        ActiveRecord::Base.verify_active_connections!
      end

      app.after do
        ActiveRecord::Base.clear_active_connections!
      end
    end
  end

  register ActiveRecordExtension
end
```
assistant