Rails idiom to avoid duplicates in has_many :through

Question

I have a standard many-to-many relationship between users and roles in my Rails app:

class User < ActiveRecord::Base
  has_many :user_roles
  has_many :ro         


        

Answer 1

I think you want to do something like:

user.roles.find_or_create_by(role_id: role.id) # saves association to database
user.roles.find_or_initialize_by(role_id: role.id) # builds association to be saved later