Fixed -- Doc'd how to use F() to sort null values.
@@ -228,6 +228,21 @@ primary key value rather than a model instance::
>> car.built_by
3
+.. _using-f-to-sort-null-values:
+
+Using ``F()`` to sort null values
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Use ``F()`` and the ``nulls_first`` or ``nulls_last`` keyword argument to
+:meth:`.Expression.asc` or :meth:`~.Expression.desc` to control the ordering of
+a field's null values. By default, the ordering depends on your database.
+
+For example, to sort companies that haven't been contacted (``last_contacted``
+is null) after companies that have been contacted::
+
+ from django.db.models import F
+ Company.object.order_by(F('last_contacted').desc(nulls_last=True))
+
.. _func-expressions:
``Func()`` expressions
@@ -971,12 +986,14 @@ calling the appropriate methods on the wrapped expression.
Returns the expression ready to be sorted in ascending order.
``nulls_first`` and ``nulls_last`` define how null values are sorted.
+ See :ref:`using-f-to-sort-null-values` for example usage.
.. method:: desc(nulls_first=False, nulls_last=False)
Returns the expression ready to be sorted in descending order.
``nulls_first`` and ``nulls_last`` define how null values are sorted.
+ See :ref:`using-f-to-sort-null-values` for example usage.
.. method:: reverse_ordering()
