has_many :through with counter_cache

Question

It is my understanding that when defining a :counter_cache option it is to be specified on the model that includes the belongs_to declaration. So I am a little unsure of how

Answer 1

I can also confirm that the method outlined by Ivica Lakatos works with Rails 6 for has_many :through relationships using a join model.

1. add patients_count to the physicians table as an integer
2. add a counter cache to the the join model (appointment.rb): belongs_to :physician, counter_cache: :patients_count