Ask A Question


You’re not receiving notifications from this thread.

How to validate model attribute

Harris Mariano asked in Rails

Hello everyone, question.

I have the following code:

class Country < ActiveRecord::Base
has_many :cities, dependent: :destroy
accepts_nested_attributes_for :cities

class City < ActiveRecord::Base
belongs_to :country
has_many :islands, dependent: :destroy

class Island < ActiveRecord::Base
belongs_to :city
validates :name , uniqueness: { scope: :city_id }

How to make island name unique within the city and within the country. Thank you in advance.

Join the discussion
Create an account Log in

Want to stay up-to-date with Ruby on Rails?

Join 81,149+ developers who get early access to new tutorials, screencasts, articles, and more.

    We care about the protection of your data. Read our Privacy Policy.

    Screencast tutorials to help you learn Ruby on Rails, Javascript, Hotwire, Turbo, Stimulus.js, PostgreSQL, MySQL, Ubuntu, and more.

    © 2024 GoRails, LLC. All rights reserved.