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

Okay there is a few more things you will need.

Don't use the field name default, its usually reserved for the database. Saving a record with a default as false will set all records to false, this isnt what you want. check to see if we are setting this record to true and the falseify.

  before_save :falsify_all_others
  def falsify_all_others
    if is_default
      self.class.where('id != ?', self.id).where('is_default').update_all(:is_default => false)
    end
  end