Question

I doing a rails project where I’m using a self joining one-to-many setup.

I have a class called User, which has many customers.
Each customer has many order lists, like this:

class User < ActiveRecord::Base
  has_many :customers, class_name: 'User', foreign_key: 'owner_id'
  belongs_to :owner, class_name: 'User'
  has_many :order_lists, dependent: :destroy

Now when I opened my rails console. I tried to do this:

user.customers.order_lists

I got this:

NoMethodError: undefined method `order_lists'

While when I try to do this:

user.customers.first.order_lists

I do receive the order lists of that customer.
But how could I recieve all the orderlists of all my customers?

Anybody an idea?

Answer 1

So you want all order_lists for all customers associated with a user?

This will do the trick:

user.customers.map(&:order_lists).flatten

Or you could make a scope on OrderList that takes a set of customer_ids like so:

scope :for_customer_ids, ->(customer_ids) {
  where("user_id IN (?)", customer_ids)
}

And then

OrderList.for_customer_ids(user.customer_ids)