Question

I have this model

class Contestcode < ActiveRecord::Base
  attr_accessible :code, :used

  def self.is_valid(code)
    valid = false
    contestcode = Contestcode.where('code = ?', code)
    Rails.logger.debug("My object: #{contestcode.inspect}");
    if (contestcode)
      valid = contestcode.used
    end
    valid
  end
end

When I try to run self.is_valid I get this error:

undefined method `used' for #<ActiveRecord::Relation:0x007ff525fde1a8>

The output of the debug statement is:

My object: [#<Contestcode id: 1, code: "aaaaa", used: false, created_at: "2013-01-23 10:21:32", updated_at: "2013-01-23 10:21:32">]

How can I get the used property of contestcode?

Answer 1

Contestcode.where returns a collection of Contestcodes. In your case, the code you are searching for is (hopefully!) unique, so it will be a collection of 1 item if it was found or 0 items if it was not.

You can see this in your debug statement – notice the square brackets around your object, which indicate that it’s in an array (actually, an ActiveRecord::Relation, which allows you to chain queries together, but it mostly behaves like an array).

What you really want here is Contestcode.where(...).first, which will extract the Contestcode from the array if it was found, or return nil if it was not.