tailieunhanh - PATTERNS OF DATA MODELING- P38

PATTERNS OF DATA MODELING- P38: 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. | 172 Chapter 13 Softcoded Values Figure Inheriting softcoding UML model. Person and Document inherit from Entity to have softcoded values. EntityType Attribute EnumValue Figure Inheriting softcoding IDEF1X model. Architecture 173 Figure Cloning softcoding UML model. The pertinent EntityTypes repeat softcoding concepts. Person PersonAttribute PersonEnumValue personlD personAttriblD personEnumValuelD logicalldentifier attributeName dataType maxLength minMultiplicity maxMultiplicity valuelnteger valueDecimal valueString valueDateTime personAttriblD FK sequenceNumber PersonValue personValuelD valuelnteger valueDecimal valueString valueDateTime personlD FK personAttriblD FK 1 1 1 1 J Document DocumentAttribute DocumentEnumValue documentID documentAttriblD documentEnumValuelD logicalldentifier attributeName dataType maxLength minMultiplicity maxMultiplicity valuelnteger valueDecimal valueString valueDateTime documentAttriblD FK sequenceNumber DocumentValue documentValuelD valueinteger valueDecimal valueString valueDateTime documentID FK documentAttriblD FK 1 1 1 - J Figure Cloning softcoding IDEF1X model. 174 Chapter 13 Softcoded Values Hardcoded Model for Populating Metadata Metadata can be difficult to grasp. It is often helpful to first prepare a hardcoded model such as Figure as an intermediate step and use it to populate the metadata. Domain experts understand hardcoded models better because they can see the concepts relationships and constraints. Person name taxpayerNumber height weight eyeColor hairColor Figure Hardcoded model. A hardcoded model can ease discussions with application experts for acquiring metadata. Mixing Hardcoded and Softcoded Attributes Application entities can have both hardcoded and softcoded values. For example the name and taxpayer number of a Person may be hardcoded. Miscellaneous data such as weight height eye color and hair color can be .