Add record to a has_and_belongs_to_many relationship

Question

I have two models, users and promotions. The idea is that a promotion can have many users, and a user can have many promotions.

class User < ActiveRecord::Bas         


        

Answer 1

user = User.find(params[:id])
promotion = Promotion.find(params[:promo_id])
user.promotions << promotion

user.promotions is an array of the promotions tied to the user.

See the apidock for all the different functions you have available.