thirdparty/google_appengine/lib/django/docs/legacy_databases.txt
author Sverre Rabbelier <srabbelier@gmail.com>
Sun, 19 Apr 2009 17:42:44 +0000
changeset 2246 c29272f640b0
parent 109 620f9b141567
permissions -rw-r--r--
Tweak the 'load balancing' algorithm In order to reduce contention we randomly skipped jobs, but this caused many jobs to end up stopping early. Now instead we keep on going until we time out (also increased the chance of doing work). Patch by: Sverre Rabbelier

==================================
Integrating with a legacy database
==================================

While Django is best suited for developing new applications, it's quite
possible to integrate it into legacy databases. Django includes a couple of
utilities to automate as much of this process as possible.

This document assumes you know the Django basics, as covered in the
`official tutorial`_.

.. _official tutorial: ../tutorial1/

Give Django your database parameters
====================================

You'll need to tell Django what your database connection parameters are, and
what the name of the database is. Do that by editing these settings in your
`settings file`_:

    * `DATABASE_NAME`
    * `DATABASE_ENGINE`_
    * `DATABASE_USER`_
    * `DATABASE_PASSWORD`_
    * `DATABASE_HOST`_
    * `DATABASE_PORT`_

.. _settings file: ../settings/
.. _DATABASE_NAME: ../settings/#database-name
.. _DATABASE_ENGINE: ../settings/#database-engine
.. _DATABASE_USER: ../settings/#database-user
.. _DATABASE_PASSWORD: ../settings/#database-password
.. _DATABASE_HOST: ../settings/#database-host
.. _DATABASE_PORT: ../settings/#database-port

Auto-generate the models
========================

Django comes with a utility that can create models by introspecting an existing
database. You can view the output by running this command::

    django-admin.py inspectdb --settings=path.to.settings

Save this as a file by using standard Unix output redirection::

    django-admin.py inspectdb --settings=path.to.settings > models.py

This feature is meant as a shortcut, not as definitive model generation. See
the `django-admin.py documentation`_ for more information.

Once you've cleaned up your models, name the file ``models.py`` and put it in
the Python package that holds your app. Then add the app to your
``INSTALLED_APPS`` setting.

.. _django-admin.py documentation: ../django_admin/

Install the core Django tables
==============================

Next, run the ``manage.py syncdb`` command to install any extra needed database
records such as admin permissions and content types::

    django-admin.py init --settings=path.to.settings

See whether it worked
=====================

That's it. Try accessing your data via the Django database API, and try editing
objects via Django's admin site.