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PATTERNS OF DATA MODELING- P42

PATTERNS OF DATA MODELING- P42: Models provide the means for building quality software in a predictable manner. Models let developers think deeply about software and cope with large size and complexity. Developers can think abstractly before becoming enmeshed in the details of writing code. Although models are beneficial, they can be difficult to construct. That is where patterns come in. Patterns provide building blocks that help developers construct models faster and better. | 192 Chapter 14 Generic Diagrams Figure 14.9 Model subject area no ports UML model. Model EntityType ExpansionMapping expansionMappingID expandableEntitylD FK innerEntitylD FK AK1.1 outerEntitylD FK AK2.1 Figure 14.10 Model subject area no ports IDEF1X model. 14.4 Model-Diagram Binding Subject Area 193 14.4 Model-Diagram Binding Subject Area Figure 14.11 and Figure 14.12 map diagram constructs to model constructs. Each diagram construct corresponds to one model construct. A model construct can appear in multiple places. These additional relationships lead to three more homomorphisms considering also the previous subject areas . Figure 14.11 Model-diagram binding subject area UML model. Diagram constructs correspond to model constructs. Model modelID Entity entitylD Port Connection I Model_Diagram portID I Port_Tab connectionID I Connection_Line Diagram diagramID diagramID FK modelID FK Entity_Icon Icon iconID Tab tablD tabID FK portID FK Line lineID lineID FK connectionID Figure 14.12 Model-diagram binding subject area IDEF1X model. 14.5 DiagramType Subject Area Figure 14.13 and Figure 14.14 determine the kind of diagram construct from the DiagramType and kind of model construct. For example the combination of a DiagramType and an EntityType determine the IconType. Thus North America and Europe may have different DiagramTypes leading to different IconTypes for a heat exchanger. A DiagramType specifies the kind of notation for a Diagram. For example IDEF1X and IE are alternative DiagramTypes for a data structure model. 194 Chapter 14 Generic Diagrams Figure 14.13 Diagram type subject area UML model. The kind of model construct determines the kind of diagram construct. Figure 14.14 Diagram type subject area IDEF1X model. An IconType is the graphical shape for an Icon. The IconType can be determined as follows. An Icon corresponds to an Entity and an Entity has an EntityType. An Icon also belongs to a Diagram of a specific DiagramType. The combination of a DiagramType