doc/book/en/03-definition-schema.en.txt
author Nicolas Chauvat <nicolas.chauvat@logilab.fr>
Fri, 14 Nov 2008 11:05:32 +0100
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.. -*- coding: utf-8 -*-
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Data Model definition (*schema*)
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The schema is the main concept of `LAX` applications as it defines the
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data model we will handle. It is based on entities types already defined
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in the library and others, more specific, we would expect to find in one or
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more Python files under the `schema` directory.
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It is important to make clear the difference between relation type and relation
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definition: a relation type is only a relation name with potentially other
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additionnal properties (see XXXX), whereas a relation definition is a complete
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triplet "<subject entity type> <relation type> <object entity type>". A relation
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type could have been implied if none is related to a relation definition of the
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schema.
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.. include:: 03-sect-stdlib-schemas.en.txt
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.. include:: 03-sect-definition-schema.en.txt