=============================
Multi-table inheritance (MTI)
=============================


..  how to test just this page:
   
    $ doctest docs/specs/projects/mti.rst
    
    doctest init:
    >>> from lino import startup
    >>> startup('lino_book.projects.mti.settings')
    >>> from lino.api.doctest import *
    >>> Person = app.Person
    >>> Restaurant = app.Restaurant
    >>> Place = app.Place
    >>> Visit = app.Visit
    >>> Meal = app.Meal


This document describes the :mod:`lino_book.projets.mti` demo project,
an application used for testing and explaining :ref:`dev.mti`.

.. currentmodule:: lino.utils.mti

.. contents::
   :local:
   :depth: 2   

  


The example database
--------------------

Here is the :xfile:`models.py` file used for this example.  This is
classical Django know-how: `Restaurant` inherits from `Place`, and
`Place` is *not* abstract.  That's what Django calls `multi table
inheritance
<https://docs.djangoproject.com/en/3.1/topics/db/models/#multi-table-inheritance>`_.

.. literalinclude:: /../../book/lino_book/projects/mti/app/models.py

>>> rt.show("app.Persons")
========
 name
--------
 Anne
 Bert
 Claude
 Dirk
 Ernie
 Fred
========
<BLANKLINE>

>>> rt.show("app.Places")
==== ===================== ======================================
 ID   name                  owners
---- --------------------- --------------------------------------
 1    Bert's pub            `Anne <Detail>`__, `Bert <Detail>`__
 2    The Chopping Shack    `Anne <Detail>`__
 3    The Abacus Well       `Claude <Detail>`__
 4    The Olive Lounge      `Ernie <Detail>`__
 5    The Autumn Bite       `Anne <Detail>`__
 6    The Private Mission   `Claude <Detail>`__
 7    Nova                  `Ernie <Detail>`__
 8    Babylon               `Anne <Detail>`__
 9    Blossoms              `Claude <Detail>`__
 10   Whisperwind           `Ernie <Detail>`__
 11   Catch                 `Anne <Detail>`__
==== ===================== ======================================
<BLANKLINE>

>>> rt.show("app.Restaurants")
==== ===================== ================= ===================== ===================
 ID   name                  serves hot dogs   owners                cooks
---- --------------------- ----------------- --------------------- -------------------
 2    The Chopping Shack    No                `Anne <Detail>`__     `Bert <Detail>`__
 3    The Abacus Well       No                `Claude <Detail>`__   `Dirk <Detail>`__
 4    The Olive Lounge      No                `Ernie <Detail>`__    `Fred <Detail>`__
 5    The Autumn Bite       No                `Anne <Detail>`__     `Bert <Detail>`__
 6    The Private Mission   No                `Claude <Detail>`__   `Dirk <Detail>`__
 7    Nova                  No                `Ernie <Detail>`__    `Fred <Detail>`__
 8    Babylon               No                `Anne <Detail>`__     `Bert <Detail>`__
 9    Blossoms              No                `Claude <Detail>`__   `Dirk <Detail>`__
 10   Whisperwind           No                `Ernie <Detail>`__    `Fred <Detail>`__
 11   Catch                 No                `Anne <Detail>`__     `Bert <Detail>`__
==== ===================== ================= ===================== ===================
<BLANKLINE>