Conceptual Data Modeling: Acknowledging the basic concepts


The basic concepts

Entity : an information object of business relevance

Attribute : a descriptor of an entity

Relationship : a graphical representation of a relationship between normally two entities, generally among n entities

Role : each side of the relationship. Qualifies each entity's implication in this relationship
Role multiplicity : the number of occurrences of the related entity
Role navigability : indicates if this entity is a child or a parent entity
Role constraint type : integrity mechanism

Key: primary or unique
Key dependency: for primary and unique keys




Building a conceptual data model

A conceptual data model consists of entities with attributes and n-ary relationships. A conceptual data model is used as a communication vehicle to build and represent the perspective of the business user's information needs.

It is possible to create a conceptual data model from the main menu, from the explorer window and from the edit toolbar.

By default, a conceptual data model comes with a diagram. Here is how to display it:
  1. Click the handle next to the data model in the explorer window, Diagram will appear.
  2. Right-click Diagram.
  3. From the pop-up menu, choose Show diagram.

The diagram appears on the right side of the explorer window. If it is empty, right-click inside the diagram window and from the pop-up menu choose Add Missing Graphical Representations.

If you do not want the data model to be automatically created with a diagram, change the default settings. See Modifying the options.