more fixes, AI

eventplanner/models.py

@@ -159,13 +159,18 @@ class EventParticipation(models.Model):
         return self.user.username
 
     def save(self, *args, **kwargs):
-        prev = EventParticipation.objects.filter(event=self.event, user=self.user)
-        if len(prev) == 0:
+        # For new objects, just save directly
+        if self.pk is None:
             super().save(*args, **kwargs)
-        else:
-            prev = prev[0]
+            return
+
+        # For existing objects, only save if values changed
+        try:
+            prev = EventParticipation.objects.get(pk=self.pk)
             if prev.status != self.status or prev.comment != self.comment:
                 super().save(*args, **kwargs)
+        except EventParticipation.DoesNotExist:
+            super().save(*args, **kwargs)
 
     @staticmethod
     def hasUserSetParticipationForAllEvents(user):