Select where not null or empty in mongoid

I modified a model so it includes a new field, such as... `field :url, :type => String` I use activeadmin, so when I create a new entry `@model.url` is empty, and in entries created before changing the schema it's nil. How do I select both? I have tried: ``` # Returns nils and strings Model.where(:url.ne => "").count # Returns strings and "" Model.where(:url.ne => nil).count # Returns strings, nils and "" Model.where(:url.ne => ["", nil]).count ``` Or, if there's a best practice for this kind of scenario please let me know.