Rails-如何仅从ActiveRecord对象获取特定记录？

Question

I get this from an ActiveRecord call:

#<ActiveRecord::Associations::CollectionProxy [
  #<CarService id: nil, car_id: nil, car_service: 1, 
               created_at: nil, updated_at: nil, car_type: 0>, 
  #<CarService id: nil, car_id: nil, car_service: 11,
               created_at: nil, updated_at: nil, car_type: 1>]>

Once I get this, I need to filter only records where car_type = "0" . How to do that without doing another database call ( WHERE car_type = "0" )?

Thank you in advance.

EDIT:

this:

car.car_services.select{|key, hash| hash['car_type'] == "1" }

does not work.

Answer 1

just convert your result to an array then filter it like this

result = car.car_services.to_a.select do |e|
     e.car_type == "0"
end

Answer 2

You can use scope in CarService model:

scope :type_ones, -> { where(car_type: 1) }

and you can use it like this:

car.car_services.type_ones

If you use enum, it will be better. Because the enum creates to scopes automatically instead of you. And of course it has more features. More about the enum .