add relation between semester_process and hours

app/models/hour.rb

@@ -12,6 +12,8 @@ class Hour < ApplicationRecord
   belongs_to :billing_expense, -> { with_deleted }, optional: true, inverse_of: 'hours'
   belongs_to :certificate, optional: true
 
+  belongs_to :semester_process_volunteer, optional: true
+
   validates :hours, presence: true, numericality: { greater_than: 0 }
   validates :meeting_date, presence: true
   validates :hourable, presence: true

app/models/semester_process_volunteer.rb

@@ -9,4 +9,5 @@ class SemesterProcessVolunteer < ApplicationRecord
     inverse_of: 'semester_processes', optional: true
 
   has_many :semester_feedbacks, dependent: :destroy
+  has_many :hours, dependent: :nullify
 end

db/migrate/20181004163636_add_relation_between_semester_process_and_hour.rb

+class AddRelationBetweenSemesterProcessAndHour < ActiveRecord::Migration[5.1]
+  def change
+    change_table :hours do |t|
+      t.references :semester_process_volunteer, foreign_key: true
+    end
+  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: 20181004144449) do
+ActiveRecord::Schema.define(version: 20181004163636) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -489,6 +489,7 @@ ActiveRecord::Schema.define(version: 20181004144449) do
     t.string "hourable_type"
     t.bigint "hourable_id"
     t.bigint "reviewer_id"
+    t.bigint "semester_process_volunteer_id"
     t.index ["billing_expense_id"], name: "index_hours_on_billing_expense_id"
     t.index ["deleted_at"], name: "index_hours_on_deleted_at"
     t.index ["hourable_type", "hourable_id"], name: "index_hours_on_hourable_type_and_hourable_id"