Part 1 Database Design

Mapping class diagrams to relational tables.

We don’t need to concern ourselves with the top two layers

Entity layer (data model) - attributes and the operations, contains the metadata, made from the class diagrams

database layer (data access / behaviour model) - the bit that reads and writes the data using operations, using transactions, made from the sequence diagram

database - persistent storage using attributes in tables

Part 2 Class Diagrams to Tables

Persistent classes - needed after application is closed

Transient classes - are removed when the application is closed

Things to worry about:

• Normalisation - how are complex things going to be stored like vectors

• Mapping - mapping metadata from OO to RDB

Mapping

Metadata in a database

Metadata for classes

Typically...

Classes = tables

Attributes = columns

Part 3 Mapping Classes to Tables

Step 1 - ATOMIC

Step 2

Step 3

Step 1 - Non Atomic

Step 2

Step 3

Step 4

Step 1 Class-type attributes