グカネータ作成 (#041) (#362)

Reviewed-on: http://git.miteruzo.com/miteruzo/btrc-hub/pulls/362
Co-authored-by: miteruzo <miteruzo@naver.com>
Co-committed-by: miteruzo <miteruzo@naver.com>

backend/app/models/post.rb

@@ -11,6 +11,17 @@ class Post < ApplicationRecord
   has_many :user_post_views, dependent: :delete_all
   has_many :post_similarities, dependent: :delete_all
   has_many :post_versions
+  has_many :gekanator_guessed_games,
+           class_name: 'GekanatorGame',
+           foreign_key: :guessed_post_id,
+           dependent: :delete_all,
+           inverse_of: :guessed_post
+  has_many :gekanator_correct_games,
+           class_name: 'GekanatorGame',
+           foreign_key: :correct_post_id,
+           dependent: :delete_all,
+           inverse_of: :correct_post
+  has_many :gekanator_question_examples, dependent: :delete_all
 
   has_many :parent_post_implications,
            class_name: 'PostImplication',