What is the best way to do per-user database connections in Rails

What is the best way to do per-user database connections in Rails?

I realize this is a poor Rails design practice, but we're gradually replacing an existing web application that uses one database per user. A complete redesign/rewrite is not feasible.

From stackoverflow Alan Hecht

• Take a look at ActiveRecord::Base.establish_connection. That's how you connect to a different database server. I can't be of much more help since I don't know how you recognize the user or map it to it's database, but I suppose a master database will have that info (and the connection info should be on the database.yml file).

  Best of luck.

  From changelog

• Put something like this in your application controller. I'm using the subdomain plus "_clientdb" to pick the name of the database. I have all the databases using the same username and password, so I can grab that from the db config file.

  Hope this helps!

  class ApplicationController < ActionController::Base
  
    before_filter :hijack_db
  
    def hijack_db
      db_name = request.subdomains.first + "_clientdb"
  
      # lets manually connect to the proper db
      ActiveRecord::Base.establish_connection(
        :adapter  => ActiveRecord::Base.configurations[ENV["RAILS_ENV"]]['adapter'],
        :host     => ActiveRecord::Base.configurations[ENV["RAILS_ENV"]]['host'],
        :username => ActiveRecord::Base.configurations[ENV["RAILS_ENV"]]['username'],
        :password => ActiveRecord::Base.configurations[ENV["RAILS_ENV"]]['password'],
        :database => db_name
      )
    end
  end
  

  From Kevin Kaske