排序

backend/community/models.py

@@ -145,8 +145,9 @@ class Topic(models.Model):
         is_new = self.pk is None
         super().save(*args, **kwargs)
         if is_new and getattr(self, 'order', 0) == 0:
-            Topic.objects.filter(pk=self.pk).update(order=self.pk)
-            self.order = self.pk
+            # 默认使用 -id 作为排序值，确保新帖子默认排在前面（order越小越靠前）
+            Topic.objects.filter(pk=self.pk).update(order=-self.pk)
+            self.order = -self.pk
 
     def __str__(self):
         return self.title