Ticket #17813: first_latest.patch

django/db/models/query.py

@@ -392 +392 @@
                 except self.model.DoesNotExist:
                     raise e
 
-    def latest(self, field_name=None):
+    def _first_or_latest(self, field_name=None, direction="-"):
         """
         Returns the latest object, according to the model's 'get_latest_by'
         option or optional given field_name.
         """
-        latest_by = field_name or self.model._meta.get_latest_by
-        assert bool(latest_by), "latest() requires either a field_name parameter or 'get_latest_by' in the model"
+        order_by = field_name or self.model._meta.get_latest_by
+        assert bool(order_by), "latest() requires either a field_name parameter or 'get_latest_by' in the model"
         assert self.query.can_filter(), \
                 "Cannot change a query once a slice has been taken."
         obj = self._clone()
         obj.query.set_limits(high=1)
-        obj.query.add_ordering('-%s' % latest_by)
+        obj.query.add_ordering('%s%s' % (direction, order_by))
         return obj.get()
 
+    def first(self, field_name=None):
+        return self._first_or_latest(field_name=field_name, direction="+")
+
+    def latest(self, field_name=None):
+        return self._first_or_latest(field_name=field_name, direction="-")
+
     def in_bulk(self, id_list):
         """
         Returns a dictionary mapping each of the given IDs to the object with