Creating an Ownership Association between User and Quiz

app/models/quiz.rb

@@ -7,6 +7,15 @@
 #  title       :string
 #  created_at  :datetime         not null
 #  updated_at  :datetime         not null
+#  user_id     :bigint
+#
+# Indexes
+#
+#  index_quizzes_on_user_id  (user_id)
+#
+# Foreign Keys
+#
+#  fk_rails_...  (user_id => users.id)
 #
 
 class Quiz < ApplicationRecord
@@ -19,6 +28,13 @@ class Quiz < ApplicationRecord
     dependent: :destroy # if a quiz is destroyed, also destroy all of its questions
   )
 
+  belongs_to(
+    :creator,
+    class_name: 'User',
+    foreign_key: 'user_id',
+    inverse_of: :quizzes
+  )
+
   validates :title, presence: true
   validates :description, presence: true
 

app/models/user.rb

@@ -22,4 +22,12 @@ class User < ApplicationRecord
   # :confirmable, :lockable, :timeoutable, :trackable and :omniauthable
   devise :database_authenticatable, :registerable,
          :recoverable, :rememberable, :validatable
+
+  has_many(
+    :quizzes,
+    class_name: 'Quiz',
+    foreign_key: 'user_id',
+    inverse_of: :creator
+  )
+
 end

db/migrate/20200228211653_add_user_fk_col_to_quizzes.rb

@@ -0,0 +1,5 @@
+class AddUserFkColToQuizzes < ActiveRecord::Migration[6.0]
+  def change
+    add_reference :quizzes, :user, foreign_key: true
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2020_02_28_205629) do
+ActiveRecord::Schema.define(version: 2020_02_28_211653) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -31,6 +31,8 @@
     t.text "description"
     t.datetime "created_at", precision: 6, null: false
     t.datetime "updated_at", precision: 6, null: false
+    t.bigint "user_id"
+    t.index ["user_id"], name: "index_quizzes_on_user_id"
   end
 
   create_table "users", force: :cascade do |t|
@@ -46,4 +48,5 @@
   end
 
   add_foreign_key "mc_questions", "quizzes"
+  add_foreign_key "quizzes", "users"
 end

db/seeds.rb

@@ -6,12 +6,24 @@
 #   movies = Movie.create([{ name: 'Star Wars' }, { name: 'Lord of the Rings' }])
 #   Character.create(name: 'Luke', movie: movies.first)
 
+u1 = User.create!(
+    email: 'alice@gmail.com',
+    password: 'password'
+)
+
+u2 = User.create!(
+    email: 'bob@gmail.com',
+    password: 'password'
+)
+
 quiz1 = Quiz.create!(
+    creator: u1,
     title: 'MVC Concepts',
     description: 'This quiz covers concepts related to the Model-View-Controller web application architecture.'
 )
 
 quiz2 = Quiz.create!(
+    creator: u2,
     title: 'Rails Concepts',
     description: 'This quiz covers concepts related to web application development using the Ruby on Rails platform.'
 )

test/fixtures/quizzes.yml

@@ -7,6 +7,15 @@
 #  title       :string
 #  created_at  :datetime         not null
 #  updated_at  :datetime         not null
+#  user_id     :bigint
+#
+# Indexes
+#
+#  index_quizzes_on_user_id  (user_id)
+#
+# Foreign Keys
+#
+#  fk_rails_...  (user_id => users.id)
 #
 
 # Read about fixtures at https://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html

test/models/quiz_test.rb

@@ -7,6 +7,15 @@
 #  title       :string
 #  created_at  :datetime         not null
 #  updated_at  :datetime         not null
+#  user_id     :bigint
+#
+# Indexes
+#
+#  index_quizzes_on_user_id  (user_id)
+#
+# Foreign Keys
+#
+#  fk_rails_...  (user_id => users.id)
 #
 
 require 'test_helper'