October 2006
Intermediate to advanced
880 pages
22h 11m
English
In chapter 4, we first distinguished between entity and value types—a central concept of ORM in Java. We must elaborate on that distinction in order for you to fully understand the Hibernate type system of entities, value types, and mapping types.
Entities are the coarse-grained classes in your system. You usually define the features of a system in terms of the entities involved. The user places a bid for an item is a typical feature definition; it mentions three entities. Classes of value types often don't even appear in the business requirements—they're usually the fine-grained classes representing strings, numbers, and monetary amounts. Occasionally, value types ...