Metadata Mapping

Holds details of object-relational mapping in metadata.

Much of the code that deals with object-relational mapping describes how fields in the database correspond to fields in in-memory objects. The resulting code tends to be tedious and repetitive to write. A Metadata Mapping allows developers to define the mappings in a simple tabular form, which can then be processed by generic code to carry out the details of reading, inserting, and updating the data.

for more details go to Chapter 13 of the online ebook at oreilly.com