Validating uniqueness of pair in Ruby on Rails’ Active Record
1 min readAug 21, 2020
I’m doing a challenge today where:
“A dose must have a description, a cocktail and an ingredient, and [cocktail, ingredient] pairings should be unique.”
To do so, we need to use uniqueness validator with scope:
class Dose < ApplicationRecord
belongs_to :cocktail
belongs_to :ingredient
validates :description, presence: true
validates :cocktail, uniqueness: { scope: :ingredient }
end
Also would work with
class Dose < ApplicationRecord
belongs_to :cocktail
belongs_to :ingredient
validates :description, presence: true
validates_uniqueness_of :cocktail, scope::ingredient
end
Flexible, right?.. Loving Ruby on Rails!