If you have built an application using scaffold then you can easily modify database search criteria. Just modify the first line in the controller script
@myController = myController.find :all
to something like
@mController = myController.find :all, :name => “Controller Name”
This is Ruby for SELECT * FROM my_controllers WHERE name=‘Controller Name’
If you are new to RoR then you should look at scaffolding to get you up and going with your database quickly.