Object-Relational Mapping

Abstract

In this chapter, I will go through the basics of object-relational mapping (ORM), which is basically mapping entities to tables and attributes to columns. I will then concentrate on more complex mappings such as relationships, composition, and inheritance. A domain model is made of objects interacting with each other. Objects and databases have different ways to store relationship information (through pointers or foreign keys). Inheritance is not a feature that relational databases naturally have, and therefore the mapping is not as obvious. I will go into some detail and show examples that will demonstrate how attributes, relationships, and inheritance are mapped from a domain model to a database.