wip multi orders

app/models/multi_group_order.rb

@@ -0,0 +1,21 @@
+class MultiGroupOrder < ApplicationRecord
+  belongs_to :multi_order
+  has_many :group_orders, dependent: :nullify
+
+  after_destroy :delete_ordergroup_invoices
+
+  def ordergroup_invoice
+    #TODO: delete if deleted
+    group_orders.joins(:ordergroup_invoice).first&.ordergroup_invoice
+  end
+
+  def ordergroup
+    ordergroup_invoice&.ordergroup
+  end
+
+  private
+
+  def delete_ordergroup_invoices
+    ordergroup_invoice&.destroy
+  end
+end