A data model describes the data that flow through the business processes in an organization. During the analysis phase, the data model presents the logical organization of data without indicating how the data are stored, created, or manipulated so that analysts can focus on the business without being distracted by technical details. Later, during the design phase, the data model is changed to reflect exactly how the data will be stored in databases and files. This chapter describes entity relationship diagramming, one of the most common data modeling techniques used in industry.
The Entity Relationship Diagram
Reading an Entity Relationship Diagram
Elements of an Entity Relationship Diagram
The Data Dictionary and Metadata
Creating an Entity Relationship Diagram
Building Entity Relationship Diagrams
Applying the Concepts at Tune Source
Validating an ERD
Balancing Entity Relationship Diagrams with Data Flow Diagrams
Appendix 6A: Normalizing ...