3.3. Object/relational mapping metadata

ORM tools require metadata to specify the mapping between classes and tables, properties and columns, associations and foreign keys, Java types and SQL types, and so on. This information is called the object/relational mapping metadata. Metadata is data about data, and mapping metadata defines and governs the transformation between the different type systems and relationship representations in object-oriented and SQL systems.

It's your job as a developer to write and maintain this metadata. We discuss various approaches in this section, including metadata in XML files and JDK 5.0 source code annotations. Usually you decide to use one strategy in a particular project, and after reading these sections you'll ...

Get Java Persistence with Hibernate now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.