Allow to delete organizers

src/pretix/base/models/event.py

@@ -282,10 +282,10 @@ class Event(EventMixin, LoggedModel):
         if not really:
             raise TypeError("Pass really=True as a parameter.")
 
-        OrderPosition.objects.all().delete(order__event=self)
-        OrderFee.objects.all().delete(order__event=self)
-        OrderPayment.objects.all().delete(order__event=self)
-        OrderRefund.objects.all().delete(order__event=self)
+        OrderPosition.objects.filter(order__event=self).delete()
+        OrderFee.objects.filter(order__event=self).delete()
+        OrderPayment.objects.filter(order__event=self).delete()
+        OrderRefund.objects.filter(order__event=self).delete()
         self.orders.all().delete()
 
     def save(self, *args, **kwargs):
@@ -301,7 +301,7 @@ class Event(EventMixin, LoggedModel):
             return []
         return self.plugins.split(",")
 
-    def get_cache(self) -> "pretix.base.cache.ObjectRelatedCache":
+    def get_cache(self):
         """
         Returns an :py:class:`ObjectRelatedCache` object. This behaves equivalent to
         Django's built-in cache backends, but puts you into an isolated environment for

src/pretix/base/models/organizer.py

@@ -82,6 +82,20 @@ class Organizer(LoggedModel):
 
         return ObjectRelatedCache(self)
 
+    def allow_delete(self):
+        from . import Order, Invoice
+        return (
+            not Order.objects.filter(event__organizer=self).exists() and
+            not Invoice.objects.filter(event__organizer=self).exists() and
+            not self.devices.exists()
+        )
+
+    def delete_sub_objects(self):
+        for e in self.events.all():
+            e.delete_sub_objects()
+            e.delete()
+        self.teams.all().delete()
+
 
 def generate_invite_token():
     return get_random_string(length=32, allowed_chars=string.ascii_lowercase + string.digits)