title: Database connection too much with ActiveRecord::Base.establish_connection
body: <p>I use multible databases with ActiveRecord. I must put <code>establish_connection db</code> in all models. But i want to call the connection of libraries file. While put <code>establish_connection db</code> in for all models Database connection count is too much . How can I do other methods? </p>
  
  <p>My project is a Ruby on Sinatra.</p>