OO models with relational databases How to use UML for modeling and designing a relational data base.

Keep in mind! No standard for UML database modeling exists! (->No tools supports rapid design from model as far as I know) The UML database model is developed from the OO applications UML data model or the other way around The UML database model are not the same model as the UML data model. Different dynamics (That’s why NF process comes in) 18-09-2018

Keep in mind! But work to make them so similar as possible….decreasing the OO-RDB impedance mismatch. Two different techniques are in use and they has different demands to design Conceptually there MUST be no difference Otherwise you may be in d… 18-09-2018

Stereo types and keys Use a key stereotype on class attributes indicating Relational key rolle In Visio 2003 use prefix or suffix in attributes properties Like <<PK>> Primary Key and <<FK>> Foreign Key. 18-09-2018

Visio Example 18-09-2018

Associations and Relationships Same association type: 1..1, 1..N, M..N.. Cardinality use standard rules Type of association Aggregation same as optional participation Composition same as mandatory participation Remember Subject-Target relationship (UML Diamond on target) . Inheritance is Generalization or Specialization be sure to set direction (Super class determines id as <<PK> sub class gets a <<FK>> from Super class) 18-09-2018