CODEWITHSUNDEEP
rubyactiverecord
Thermatix
Thermatix

Reputation: 2929

Activerecord relation not nullifying dependent despite being asked to do so

I'm getting the following error:

PG::ForeignKeyViolation: ERROR: update or delete on table "sites" violates foreign key constraint "fk_rails_b1cb5ea385" on table "domains" DETAIL: Key (id)=(1) is still referenced from table "domains". : DELETE FROM "sites" WHERE "sites"."id" = $1

This is because there is a Domain record that has a reference to the site being deleted, I know this because manually removing the site_id causes the error to go away (of course this is not the way to do this, this was done for checking purposes only).

However as can be seen in the model:

class Site < ApplicationRecord
  enum environment: %i{development staging production}

  belongs_to :project
  belongs_to :client
  has_one :domain, dependent: :nullify
  has_many :servers, through: :domain

end

I am indeed asking active record to nullify the domain ( though I am considering outright destroying it, that isn't relevant to this issue).

This association is also used in Server:

class Server < ApplicationRecord

  before_save :set_domains, if: :sites_id_changed?
  has_many :domains, dependent: :nullify
  has_many :sites, through: :domains

  def clients
    self.sites.map(&:client).flatten
  end

  def set_domains
    domains = get_domains Site.where(id: self.site_ids).all
    domains += get_domains domains,:domains
    self.domains = domainsprimary_domains 
  end


  private
    def get_domains(object,meth=:domain)
      objects.first.blank? ? [] : objects.map(&meth).flatten
    end
end

and Domain:

class Domain < ApplicationRecord

  alias_attribute :aliases, :domains
  alias_attribute :alias_of, :domain

  has_many :domains, dependent: :nullify
  belongs_to :domain, optional: true

  belongs_to :site, optional: true
  belongs_to :server, optional: true

  def alias?
    !self.alias_of.blank?
  end


  accepts_nested_attributes_for :domains, allow_destroy: true

end

Why despite being asked to so do is active record not nullifying the reference to site table in the domain table despite being asked (seemingly at least) to do so?

Upvotes: 1

Views: 1295

Answers (1)

Nick Schwaderer
Nick Schwaderer

Reputation: 1038

I have run into something similar in the past. You are correct that this is a situation where you are running into a database-level foreign key constraint.

If you're using PG, for example, here are some helpful docs with more information on the constraint in general.

As far as solving your actual issue, the SO response that helped me overcome this error and get things working again I found here.

Let me know if that works/helps! :)

Upvotes: 3

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