Modelling Business Information: Entity relationship and class modelling for business analysts by Keith Gordon

Author:Keith Gordon
Language: eng
Format: epub, pdf
Published: 2017-04-05T04:00:00+00:00

Figure 5.5 shows the equivalent UML class model structure.

Figure 5.5 EMPLOYEE expanded (shown in UML class modelling notation)

UNIQUE IDENTIFIERS

An entity type represents a set of entities, where an entity is thing of interest to the business about which information needs to be recorded. An attribute of an entity type is a property that is used to qualify, identify, classify, quantify or in some other way express the state of an entity.

If we wish to record information about an entity and then to later retrieve that information (for, why else would we be recording the information), that entity must be identifiable in some way. Each entity type must, therefore, have some characteristics that make each instance of the entity type uniquely identifiable. In that way, each instance of an entity type will be distinctly identifiable from all other instances of that entity type.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.