#414

backend/app/models/event.rb

@@ -0,0 +1,9 @@
+class Event < ApplicationRecord
+  has_many :post_versions
+  has_many :tag_versions
+  has_many :material_versions
+  has_many :tag_description_versions
+  has_many :tag_group_versions
+
+  belongs_to :created_by_user, class_name: 'User', optional: true
+end

backend/app/models/material_version.rb

@@ -11,7 +11,5 @@ class MaterialVersion < ApplicationRecord
   belongs_to :parent, class_name: 'Material', optional: true
   belongs_to :updated_by_user, class_name: 'User', optional: true
 
-  def export_paths_hash
-    export_paths_json || {}
-  end
+  def export_paths_hash = export_paths_json || { }
 end

backend/app/models/version_record.rb

@@ -19,6 +19,8 @@ module VersionRecord
 
     belongs_to :created_by_user, class_name: 'User', optional: true
 
+    belongs_to :event
+
     enum :event_type, event_type_map, prefix: true, validate: true
 
     validates :version_no, presence: true, numericality: { only_integer: true, greater_than: 0 }