===============================================
Upgrading from Django's previous comment system
===============================================

Prior versions of Django included an outdated, undocumented comment system. Users who reverse-engineered this framework will need to upgrade to use the
new comment system; this guide explains how.

The main changes from the old system are:

* This new system is documented.

* It uses modern Django features like :doc:`forms </topics/forms/index>` and
  :doc:`modelforms </topics/forms/modelforms>`.

* It has a single ``Comment`` model instead of separate ``FreeComment`` and
  ``Comment`` models.

* Comments have "email" and "URL" fields.

* No ratings, photos and karma. This should only effect World Online.

* The ``{% comment_form %}`` tag no longer exists. Instead, there's now two
  functions: ``{% get_comment_form %}``, which returns a form for posting a
  new comment, and ``{% render_comment_form %}``, which renders said form
  using the ``comments/form.html`` template.

* The way comments are include in your URLconf have changed; you'll need to
  replace::

        (r'^comments/', include('django.contrib.comments.urls.comments')),

  with::

        (r'^comments/', include('django.contrib.comments.urls')),

Upgrading data
--------------

The data models for Django's comment system have changed, as have the
table names. Before you transfer your existing data into the new comments
system, make sure that you have installed the new comments system as
explained in the
:doc:`quick start guide </ref/contrib/comments/index>`.
This will ensure that the new tables have been properly created.

To transfer your data into the new comments system, you'll need to directly
run the following SQL:

.. code-block:: sql

    BEGIN;

    INSERT INTO django_comments 
        (content_type_id, object_pk, site_id, user_name, user_email, user_url,
        comment, submit_date, ip_address, is_public, is_removed)
    SELECT
        content_type_id, object_id, site_id, person_name, '', '', comment,
        submit_date, ip_address, is_public, not approved
    FROM comments_freecomment;

    INSERT INTO django_comments 
        (content_type_id, object_pk, site_id, user_id, user_name, user_email,
        user_url, comment, submit_date, ip_address, is_public, is_removed)
    SELECT 
        content_type_id, object_id, site_id, user_id, '', '', '', comment,
        submit_date, ip_address, is_public, is_removed
    FROM comments_comment;

    UPDATE django_comments SET user_name = (
        SELECT username FROM auth_user 
        WHERE django_comments.user_id = auth_user.id
    ) WHERE django_comments.user_id is not NULL;
    UPDATE django_comments SET user_email = (
        SELECT email FROM auth_user 
        WHERE django_comments.user_id = auth_user.id
    ) WHERE django_comments.user_id is not NULL;
    
    COMMIT;
