Question

Simple model:

class hat
  embedded_in :owner
  field :color
end

class owner
  embedds_one :hat
  referenced_in :house
  field :name
end

class house
  references_one :owner
  field :number
end

So simply puts, we have collection of houses that are associated to an owner, and the owner can have a colored hat.

I can simply sort the house by their number:

House.all.order_by( [[ :number, :asc ]])

But what I want is ordering the house, by the name of their owner, ideally I would like to write:

House.all.order_by( [[ :'owner.name', :asc ]])

But it does not work…

And even further I would like to be able to sort the houses by the color of the owner’s hat

House.all.order_by( [[ :'owner.hat.color', :asc ]])

Any idea how I can achieve this without rewriting everything if possible 🙂

Thanks

ALex

Answer 1

Dot notation is possible only for embedded documents, but you have 2 collections – houses and owners.
In one of the Owner records in MongoDB you have only field house_id, in one of the House records you dont have any connection to Owner model.
So the only way is to fetch all Houses and then to sort achieved collection using Enumerable#sort.