Best way to find records with an attachment?

[dan]

I have Car model which can have an attached Photo. Using ActiveRecord, I'd like to find just the Cars with a Photo attached. I've been checking for a null photo_data column, but I'm wondering if this is the best way, or if there's built-in method I should be using to do this. I can't seem to find one.

Currently it looks like this:

Car.where(photo_data: nil)

And the scope:

scope :photographed, -> { where.not(photo_data: nil) }

Thanks for any tips!

[benkoshy]

I do not know of a better way, nor can I think of a better way, than what you've done above.