JPA - Object-Relational Mapping (ORM)

About

JPA standardizes the important task of object-relational mapping by using:

• Entity annotations
• XML Mapping Files (orm.xml)
• programmatically (without Entity) (ie Dynamic Persistence)

to map objects into one or more tables of a database.

The JPA specification explicitly defines the object-relational mapping, rather than relying on vendor-specific mapping implementations.

The mapping metadata are an union of:

• all mapping files
• and Entity annotations

Articles Related

Type

• top-down: Generating database tables from entity beans

Documentation / Reference

• About Object-Relational Mapping
• Interoperability Happens - The Vietnam of Computer Science