api discount and change tax

db/migrate/20231005055229_add_reference_to_parent_item_to_sale_items.rb

@@ -0,0 +1,6 @@
+class AddReferenceToParentItemToSaleItems < ActiveRecord::Migration[5.1]
+  def change
+    add_column :sale_items, :parent_id, :string, limit: 16, default: nil, after: :sale_item_id
+    add_index :sale_items, :parent_id
+  end
+end

db/migrate/20231005055250_add_discount_to_sale_items.rb

@@ -0,0 +1,6 @@
+class AddDiscountToSaleItems < ActiveRecord::Migration[5.1]
+  def change
+    add_column :sale_items, :discount_type, :string, after: :price
+    add_column :sale_items, :discount, :decimal, precision: 10, scale: 2, after: :price
+  end
+end