Fixes jieter#854

I don't think this is perfect but I haven't dug in deep enough to know
what would be.

django_tables2/columns/base.py

@@ -397,7 +397,12 @@ def order(self, queryset, is_descending):
         returns:
             Tuple (QuerySet, boolean)
         """
-        return (queryset, False)
+        from django.db.models import F, OrderBy
+
+        if self.order_by or self.accessor:  # TODO: self.orderable
+            return queryset, OrderBy(F(self.order_by or self.accessor), descending=is_descending)
+
+        return queryset, None
 
     @classmethod
     def from_field(cls, field, **kwargs):

django_tables2/data.py

@@ -197,8 +197,8 @@ def order_by(self, aliases):
                 columns ('-' indicates descending order) in order of
                 significance with regard to data ordering.
         """
-        modified_any = False
         accessors = []
+        orderables = tuple()
         for alias in aliases:
             bound_column = self.table.columns[OrderBy(alias).bare]
             # bound_column.order_by reflects the current ordering applied to
@@ -210,14 +210,15 @@ def order_by(self, aliases):
                 accessors += bound_column.order_by
 
             if bound_column:
-                queryset, modified = bound_column.order(self.data, alias[0] == "-")
+                # We have to pass queryset because ordering could be on an annotation that was
+                #  added for sorting
+                self.data, ordering = bound_column.order(self.data, alias[0] == "-")
 
-                if modified:
-                    self.data = queryset
-                    modified_any = True
+                orderables = orderables + (ordering,)
 
         # custom ordering
-        if modified_any:
+        if orderables:
+            self.data = self.data.order_by(*orderables)
             return
 
         # Traditional ordering