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Practical introduction into Object-Role Modeling (ORM)

Good news for you if you wanted to create information models based on Object-Role Modeling (ORM) (see Background information below) but were looking for a good introduction into this method. In May this year Terry Halpin namely published ‘Object-Role Modeling Fundamentals. A Practical Guide to Data Modeling with ORM’.

Terry Halpin. Object-Role Modeling Fundamentals. A Practical Guide to Data Modeling with ORM. Technics Publications LLC, 2015, 192 pagina’s,

This concise introduction into ORM is a welcome addition to the ‘Big Brown Book’ that was published in 2008 by Terry Halpin and Tony Morgan: ’Information Modeling and Relational Databases’.

In ‘Fundamentals’ first a general introduction is given into information modelling and in particular Fact-Based Modeling (FBM) is explained. After that ORM is explained by going through the steps of the so-called Conceptual Schema Design Procedure (CSDP) by means of examples. This procedure comprises 7 steps to describe an area of interest (‘Universe of Discourse’, UoD).

The explanation is very accessible because of the many examples that are given by means of diagrams. Besides that Terry has made the explanation practical by introducing the reader to an ORM modeling tool, NORMA. This tool is a free add-on to Visual Studio of Microsoft, of which the free Community version can be used. So Terry does not only explain ORM but also NORMA. Maybe this is a drawback for the tenability of the book: a new version of NORMA makes that the book will not be up-to-date anymore here and there.

In two appendices generating SQL code from an ORM model is discussed and an overview of the symbols that are used in ORM diagrams is given.

The book is highly recommended to those who want to start with ORM. Anyway, the book can perfectly be used without that the reader wants to apply NORMA in creating ORM models.

Background information

For example at selecting or developing software, or drawing up or interpreting laws and regulations, it is important that a subject or situation is described unambiguously. In big words: the semantics of an area of interest (‘Universe of Discourse’, UoD) must be modelled.

Fact-Based Modeling (FBM) is a way to capture those semantics. (Information) models that are created by applying FBM have as characteristic that an area of interest is described without anticipating a technical solution. Also with FBM the semantics are described in controlled natural language, so comprehensible to people who are expert in their domain but not necessarily in IT.

There are several variants of Fact-Based Modeling. One of them is Object-Role Modeling, abbreviated as ORM.