Contents Object Mapping Description Relevant Links Object Mapping Papers Object Mappings Description Systems are often developed where mappings to a non-object environment is required. Quote often, relational calculus and the maturity of a relational database is exactly what one needs. Other times it might be the corporate policy to use a certain persistence storage for backwards compatibility etc. Making your object persistent in a non-OO world can cause a lot of grief if you haven't done this before. The primary problems that one has to deal with is an impedance mismatch.
Objects have hierarchies, types, compositions, polymorphism.
Objects put together code and data to form good logical pieces. Non object storage technologies are more data centric. They provide things such as rows, tables, relational calculus, permanent storage, and routines to quickly access and manipulate the data. There are some common patterns for dealing with this mismatch and these pages focus on how to deal with such issues. A VisualAge implementation of a Persistence Framework for persisting domain objects in a relational database.