doc/book/en/03-00-definition-schema.en.txt
author Laure Bourgois <Laure.Bourgois@logilab.fr>
Tue, 25 Nov 2008 17:44:54 +0100
changeset 144 3159772915c4
parent 114 9ecd54ea0634
permissions -rw-r--r--
cleaning code

.. -*- coding: utf-8 -*-

Data Model definition (*schema*)
================================

The schema is the main concept of `LAX` applications as it defines the
data model we will handle. It is based on entities types already defined
in the library and others, more specific, we would expect to find in one or
more Python files under the `schema` directory.

It is important to make clear the difference between relation type and relation
definition: a relation type is only a relation name with potentially other
additionnal properties (see XXXX), whereas a relation definition is a complete
triplet "<subject entity type> <relation type> <object entity type>". A relation
type could have been implied if none is related to a relation definition of the
schema.


.. include:: 03-10-stdlib-schemas.en.txt
.. include:: 03-11-definition-schema.en.txt