🌱 Validate number of association

🌿 What? §

• 🌱 If you have a People model and a Vehicle model, every people has_many vehicles but you want to set maximum for number of vehicles which a people can has. You can use following command below:

# vehicle.rb
class Vehicle
  belongs_to :people
end
 
# people.rb
class People
  has_many :vehicles
 
  validates :vehicles, length: { maximum: 2 }
end

🌿 Refer §

https://til.hashrocket.com/posts/egegrgsdnj-limiting-object-counts-in-rails-associations-