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

In your controller code you could do something like this.... please note you're probably taking Item2 as a param[...] so you can interchange that below

@items_to_be_falsified = Item.where('id != ?', Item2.id)

@items_to_be_falsified.each do |item|
  item.default = false
  item.save
end

Please note when you get this working, its good practice to move this into the model, make it into a function and call it like Item2.falsify_all_others like below

def falsify_all_others
  Item.where('id != ?', self.id).each do |item|
    item.default = false
    item.save
  end
end

Enjoy!

Answer 2

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