如何通过铁轨交叉两个ActiveRecord关系对象？

Question

I need to find the intersection result of two ActiveRecord Relation objects. This is my Controller

if params.has_key?(:car_insurance_type_id)
  car_insurance_type = CarInsuranceType.find_by(id: params[:car_insurance_type_id])
else
  car_insurance_type = CarInsuranceType.find_by(id: 1)
end

@breadcrumb_title = car_insurance_type.title

car_insurance_objects_private = car_insurance_type.car_insurance_objects

if params.has_key?(:car_model_id)
  car_model_search = CarModel.find_by(id: params[:car_model_id])

  if car_model_search
    car_insurance_objects_from_model = car_model_search.car_insurance_objects
  end

end

car_insurance_objects_private = car_insurance_objects_private & car_insurance_objects_from_model

But "&" method didn't work for ActiveRecord object

This is my model

class CarInsuranceType < ActiveRecord::Base

  has_many :car_insurance_objects ,dependent: :destroy

end

class CarInsuranceObject < ActiveRecord::Base

  belongs_to :insurance_company
  belongs_to :car_insurance_type
  has_and_belongs_to_many :car_models

end

class CarModel < ActiveRecord::Base

  belongs_to :car_brand
  has_and_belongs_to_many :car_insurance_objects ,dependent: :destroy

end

So how can i find the intersection result between two CarInsuranceObject that one belongs_to car_insurance_type and another one that has_and_belongs_to_many car_models?

Thanks!

Answer 1

As far as I understand, you need to query DB for CarInsuranceObject 's of specified CarInsuranceType and CarModel . Why not to simplify all this stuff:

car_insurance_type_id = params[:car_insurance_type_id] || 1
car_insurance_objects_private = car_model_search.car_insurance_objects.where(car_insurance_type_id: car_insurance_type_id)

Btw, there is really long names for variables.