Join table cannot update or destroy throw error of no primary key

[starkshaw]

Steps to reproduce

Have models as follow:

class Event < ApplicationRecord
  belongs_to :deal
  has_many :events_users
  has_many :users, through: :events_users
end

class Deal < ApplicationRecord
  belongs_to :team
  has_many :deals_users
  has_many :users, through: :deals_users
  has_many :events
end

class Team < ApplicationRecord
  has_many :deals
  has_many :team_users
  has_many :users, through: :team_users
end

class User < ApplicationRecord
  has_one :team, through: :team_user
  has_one :team_user
  has_and_belongs_to_many :deals
  has_and_belongs_to_many :events
end

class EventsUser < ApplicationRecord
  belongs_to :event
  belongs_to :user
  validates_uniqueness_of :event_id, scope: :user_id
  enum status: [:pending, :accepted, :maybe, :rejected]
end

class DealsUser < ApplicationRecord
  belongs_to :user
  belongs_to :deal
  validates_uniqueness_of :deal_id, scope: :user_id
end

class TeamUser < ApplicationRecord
  belongs_to :user
  belongs_to :team
  validates_uniqueness_of :team_id, scope: :user_id
  validates_uniqueness_of :user_id
end

Expected behavior

The join tables, EventsUser, DealsUser, TeamUser can be updated or deleted.

Actual behavior

It can only be created, the update will throw

ActiveRecord::UnknownPrimaryKey: Unknown primary key for table events_users in model EventsUser.
Can not validate uniqueness for persisted record without primary key.

and destroy will throw

NoMethodError: undefined method `to_sym' for nil:NilClass

These following are my testing procedures in rails c.

eu = EventsUser.first
eu.status = "maybe"
eu.save (throw update error)
eu.destroy (throw destroy error)
eu (it exists)
eu.status (return the status)

status is an enum in model, and defined in migration as such:

t.integer :status, default: 0

System configuration

Rails version:
Rails 5.0.0.rc1
Ruby version:
ruby 2.3.1p112 (2016-04-26 revision 54768) [x86_64-darwin15]

Reference

#21304

[maclover7]

cc @sgrif

[prakashmurthy]

Tried reproducing this behavior with a demo app; could not reproduce the buggy behavior. The join tables can be updated and deleted as per normal expectation.

The demo app is at https://github.com/prakashmurthy/join_table_issue_demo

Tried with both 5.0.0 and 5.0.0.rc1.

Ruby version: ruby 2.3.1p112 (2016-04-26 revision 54768) [x86_64-darwin15]

Not sure what I am missing....

[ibussieres]

Experiencing the exact same problem, also with a joint table. Rails 5.0.0.

Extract from db/schema.rb

create_table "likes", id: false, force: :cascade do |t|
    t.integer  "item_id"
    t.integer  "owner_id"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
    t.index ["item_id", "owner_id"], name: "index_likes_on_item_id_and_owner_id", unique: true, using: :btree
end

@prakashmurthy's example does not use joint indices. Perhaps that is the root problem ?

[ibussieres]

fwiw, I changed it to seperated indices and still have the same issue.

[prakashmurthy]

Created a bug_report_template script for this issue; the behavior is not being reproduced by the script. Hopefully, it will help identify the difference that is causing the issue for @starkshaw and @ibussieres .

Script to reproduce the issue with join table update and delete

begin
  require "bundler/inline"
rescue LoadError => e
  $stderr.puts "Bundler version 1.10 or later is required. Please update your Bundler"
  raise e
end

gemfile(true) do
  source "https://rubygems.org"
  # Activate the gem you are reporting the issue against.
  gem "activerecord", "5.0.0"
  gem "sqlite3"
end

require "active_record"
require "minitest/autorun"
require "logger"

# Ensure backward compatibility with Minitest 4
Minitest::Test = MiniTest::Unit::TestCase unless defined?(Minitest::Test)

# This connection will do for database-independent bug reports.
ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:")
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :teams, force: true do |t|
    t.string :name
  end

  create_table :deals, force: true do |t|
    t.string :name
    t.integer :team_id
  end

  create_table :events, force: true do |t|
    t.string :name
    t.integer :deal_id
  end

  create_table :users, force: true do |t|
    t.string :first_name
    t.string :last_name
  end

  create_table :events_users, force: true do |t|
    t.integer :event_id
    t.integer :user_id
    t.integer :status, default: 0
  end

  create_table :deals_users, force: true do |t|
    t.integer :deal_id
    t.integer :user_id
    t.integer :status, default: 0
  end

  create_table :team_users, force: true do |t|
    t.integer :team_id
    t.integer :user_id
    t.integer :status, default: 0
  end
end

class ApplicationRecord < ActiveRecord::Base
  self.abstract_class = true
end

class Event < ApplicationRecord
  belongs_to :deal
  has_many :events_users
  has_many :users, through: :events_users
end

class Deal < ApplicationRecord
  belongs_to :team
  has_many :deals_users
  has_many :users, through: :deals_users
  has_many :events
end

class Team < ApplicationRecord
  has_many :deals
  has_many :team_users
  has_many :users, through: :team_users
end

class User < ApplicationRecord
  has_one :team, through: :team_user
  has_one :team_user
  has_and_belongs_to_many :deals
  has_and_belongs_to_many :events
end

class EventsUser < ApplicationRecord
  belongs_to :event
  belongs_to :user
  validates_uniqueness_of :event_id, scope: :user_id
  enum status: [:pending, :accepted, :maybe, :rejected]
end

class DealsUser < ApplicationRecord
  belongs_to :user
  belongs_to :deal
  validates_uniqueness_of :deal_id, scope: :user_id
end

class TeamUser < ApplicationRecord
  belongs_to :user
  belongs_to :team
  validates_uniqueness_of :team_id, scope: :user_id
  validates_uniqueness_of :user_id
end

User.create(first_name: "Almaz", last_name: "Ayana")
User.create(first_name: "Vivian", last_name: "Cheruiyot")

Team.create(name: "10000m")
Team.create(name: "100m")

Deal.create(name: "Half Off", team_id: 1)
Deal.create(name: "BOGO", team_id: 2)

Event.create(name: "Christmas", deal_id: 1)
Event.create(name: "Halloween", deal_id: 1)

EventsUser.create(user_id: 1, event_id: 1)
EventsUser.create(user_id: 2, event_id: 1)

TeamUser.create(user_id: 1, team_id: 1)
TeamUser.create(user_id: 2, team_id: 2)

DealsUser.create(user_id: 1, deal_id: 1)
DealsUser.create(user_id: 2, deal_id: 2)

class BugTest < Minitest::Test
  def test_join_table_update
    eu = EventsUser.first
    eu.status = "maybe"
    eu.save
    assert_equal "maybe", EventsUser.first.status
    eu.destroy
    assert_equal true, eu.destroyed?
  end
end

[ibussieres]

It works if I remove id: false. I can work around the problem by testing uniqueness in the model, but it leaves me with a useless id field in a join table.

[sgrif]

Active Record doesn't have built in support for composite primary keys. You'll need to remove the validates_uniqueness_of. If this isn't an error you expect the user to be able to recover from (e.g. it's just to enforce data integrity), you can use a unique index on the database for the same purpose.

[sgrif]

Actually if you can reproduce this by deleting through associations, there probably is a real issue here. Please update with a repro script if that's the case.

[lhammond]

happening for me on 5.0.0.1

[stale]

This issue has been automatically marked as stale because it has not been commented on for at least three months.
The resources of the Rails team are limited, and so we are asking for your help.
If you can still reproduce this error on the 5-1-stable branch or on master, please reply with all of the information you have about it in order to keep the issue open.
Thank you for all your contributions.