How to do the following in case of Ruby on rails

Question

How to do subdomains & seperated databases for a rails app as shown in tutorial below for php

I am a newbie with ruby & ruby on rails as well so I would like now that is any thing possible which shown in this tutorial by anatgarg in php

1. subdomains
2. multiples databases
3. database switching based on subdomain

Answer 1

1. You can see screencasts @ Railscasts episode #221 Subdomains in Rails 3
2. Actually, I never use multiples databases, but I have try use multiples schemas with postgresql, see @ Railscasts episode #389 Multitenancy with PostgreSQL pro
3. You can use gem apartment for switching schema based on subdomain

I can't explain one by one because it would be too long to be explained. Hope this help