Fixed #20561 -- Emphasized that QuerySet.distinct([*fields]) is only supported by Postgres.

    :meth:`values()` together, be careful when ordering by fields not in the

    :meth:`values()` call.

You can pass positional arguments (``*fields``) in order to specify the names

of fields to which the ``DISTINCT`` should apply. This translates to a

``SELECT DISTINCT ON`` SQL query. Here's the difference. For a normal

``distinct()`` call, the database compares *each* field in each row when

On PostgreSQL only, you can pass positional arguments (``*fields``) in order to

specify the names of fields to which the ``DISTINCT`` should apply. This

translates to a ``SELECT DISTINCT ON`` SQL query. Here's the difference. For a

normal ``distinct()`` call, the database compares *each* field in each row when

determining which rows are distinct. For a ``distinct()`` call with specified

field names, the database will only compare the specified field names.

.. note::

    This ability to specify field names is only available in PostgreSQL.

.. note::

    When you specify field names, you *must* provide an ``order_by()`` in the

    QuerySet, and the fields in ``order_by()`` must start with the fields in

    value in column ``a``. If you don't specify an order, you'll get some

    arbitrary row.

Examples::

Examples (those after the first will only work on PostgreSQL)::

    >>> Author.objects.distinct()

    [...]