joins condition on active record

Question

I have two Models

Order has_many State(s)
State belongs_to Order
a State has an attribute named 'kind'

I'm trying to express the following query with active record: 'all the orders that have current_state.kind = :something',

the current_state is the last created state for an order.

I also also add in the model :current_state as a has_one association:

has_one :current_state, -> { order('created_at DESC').limit(1) }, class_name: 'State'

but it doesn't help

Answer 1

this is the best solution I've found so far

Order.joins(:states).where("states.id IN (SELECT MAX(id) FROM states GROUP BY order_id)").where("states.kind"=>"checkedin")