Wow, this is my first post for Ruby on Rails and Ruby in general! So what I’m trying to do is very simple: create a self join relationship for the user table like a parent/child relationship. However, Rails always complains about the missing parent even if the relationship is optional (my assumption).
Very simple, common use case
I followed this guide http://guides.rubyonrails.org/association_basics.html and below is my sample code:
class User < ApplicationRecord has_many :sub_merchants, class_name: 'User', foreign_key: 'parent_id' belongs_to :parent, class_name: 'User' end
and the table columns:
User: - id - parent_id - email - password - created_at - updated_at
As you can see, I’m trying to have a user table where a user can have parent (or not).
The parent_id column is just newly added in our existing codebase. The result is that some of the test cases started failing. See example below:
FactoryGirl.create :user, parent: nil
I have already defined a factory helper for user and I just specify
parent: nil above to demonstrate that it should work since my assumption is that
belongs_to is optional. However, I get this error:
Parent must exist
Fortunately, the fix is easy. Just declare the
belongs_to as optional which I initially assume to be the default (which seems not).
class User < ApplicationRecord has_many :sub_merchants, class_name: 'User', foreign_key: 'parent_id' belongs_to :parent, class_name: 'User', optional: true end