ProAce - Custom Software Development Austin, Texas » information modeling

External Uniqueness Constraints

Michael — Thu, 04 Mar 2010 15:12:08 +0000

External uniqueness constraints are very closely related to internal uniqueness constraints. The difference is external uniqueness constraints span multiple roles instead of just one. Since the concept isn’t too big of a stretch we’re going…

Mandatory Role Constraints

Rex Morgan — Wed, 03 Mar 2010 18:15:47 +0000

The Mandatory role constraint is used in ORM as a way to model that an entity is required to play a role in a particular fact.

For a quick example, this is what a fact looks like with no mandatory…

Internal Uniqueness Constraints

Michael — Thu, 18 Feb 2010 15:47:54 +0000

The simplest and most commonly used constraint in ORM is the internal uniqueness constraint. This constraint basically specifies a one-to-many relationship on a role. The easiest way to show this is through an example. Let's use the following fact: The Student with ID 1 has Name 'Bob'

ORM Basics: Entities, Values, Roles, and Facts

Jarrod — Thu, 18 Feb 2010 00:38:40 +0000

Object-role modeling is a fantastic tool that allows one to construct incredibly rich and complex information models. Because of this, it can be difficult to identify a starting point to jump in and begin learning ORM. At ProAce, we feel that identifying the primitive building blocks and working our way up is the natural way to begin teaching any new technique. For ORM, these building blocks are the fundamental types: entities, values, roles and facts.

Object-Role Modeling kickoff

Josh Arnold — Fri, 12 Feb 2010 23:03:10 +0000

Our team has been having some great discussions on Object-Role Modeling this month and I really like the topics that we’ve covered. While ORM is a pivotal part of our internal process, it’s been very interesting to discuss how/when/where/why we actually use it. More importantly, discussing the pros/cons has been really enlightening to identify some of our inefficiencies and brainstorm over ways to help improve our process.

Business domains for developers

Josh Arnold — Tue, 02 Feb 2010 22:00:11 +0000

Among many of its other benefits, Domain-Driven Design has provided our team with a way of approaching software from a domain-centric approach. Domains are often complex; with so much focus on the model and logic in complex domain designs, it’s important to keep track of all of the pieces. Here at ProAce, we use a method called Object-Role-Modeling.