bug fixing using cursor

app/models/client.rb

@@ -13,4 +13,8 @@ class Client < ApplicationRecord
   def editable?
     referenced_count <= 1
   end
+
+  def display_name
+    "#{company_name} (#{lastname}, #{firstname})"
+  end
 end

app/models/project.rb

@@ -1,5 +1,5 @@
 class Project < ApplicationRecord
-  has_many :subprojects, inverse_of: :project
+  has_many :subprojects, inverse_of: :project, dependent: :destroy
   accepts_nested_attributes_for :subprojects, allow_destroy: true, reject_if: :all_blank
 
   validates :name, presence: true