Rails 3 app model how ensure only one boolean field set to true at a time

Question

I have a Logo model that has fields of name:string, default:boolean. I want the true value to be unique, so that only one item in the database can be set to true at once. How do

Answer 1

I also recommend falsifying all your records then making them true.

add_column :users, :name ,:boolean, default: false