How to write data to two tables?

Question

Ruby on Rails

There are two tables (cars and colors).
The cars table has
id brand power color_id fields
The colors table has
id color rarity fields
The content of the models

class Car < ActiveRecord::Base
  belongs_to :color
  ...
end

class Color < ActiveRecord::Base
  ...
end

After creating the basic data about the car, we can move on to creating additional characteristics. How to write in the color_id field the id of the created car color when creating color characteristics?

Answer 1

model car
belongs_to :color
controller
@car = Car.new(:power => 106)
@car.color = Color.where(:id => 6).first
@car.save Advertisement
site?

Answer 2

This is just a report on the conversion of a project from a previous version to a newer one, close it and move on. You can read what kind of warnings, maybe something useful will be there.

Answer 3

put the picture, please, on habrastorage - nothing is visible,
but so far no errors are visible,
one warning,
but you can live and work with it further