FIX: Associate category logo and background to uploads record.

db/migrate/20161202034856_add_uploads_to_categories.rb

@@ -0,0 +1,21 @@
+class AddUploadsToCategories < ActiveRecord::Migration
+  def up
+    add_column :categories, :uploaded_logo_id, :integer, index: true
+    add_column :categories, :uploaded_background_id, :integer, index: true
+
+    transaction do
+      Category.find_each do |category|
+        logo_upload = Upload.find_by(url: category.logo_url)
+        category.uploaded_logo_id = logo_upload.id if logo_upload
+
+        background_upload = Upload.find_by(url: category.background_url)
+        category.uploaded_background_id = background_upload.id if background_upload
+
+        category.save!
+      end
+    end
+
+    remove_column :categories, :logo_url, :string
+    remove_column :categories, :background_url, :string
+  end
+end