fix

alkatorapi/views.py

@@ -126,8 +126,16 @@ def register_racer(request):
     product.quantity -= 1
     product.save()
 
+    invoice = Invoice(
+        invoice_id=invoice_id,
+        user=user,
+        total_price=price,
+        address=profile.address,
+    )
+    racer.save()
     racer = Racer(
         product=product,
+        invoice=invoice,
         quantity=1,
         profile = profile,
         first_name = request.POST['first_name'],
@@ -139,13 +147,6 @@ def register_racer(request):
         alkator_class = ALKATOR_CLASS,
         price=price,
     )
-    invoice = Invoice(
-        invoice_id=invoice_id,
-        user=user,
-        total_price=price,
-        address=profile.address,
-    )
-    racer.save()
     invoice.items.set([racer])
     invoice.save()