Introduction for Mapping Objects to Tables

Object-orientation and the relational model are different paradigms of programming. When objects need to be stored in relational databases, the gap between the two different sights needs to be bridged. If only data abstraction modules have to be mapped to a relational database, life is comparably easy [Kel+97 ]. With full blown object models the concepts of object oriented programming have to be mapped to relational table structures. These are:

Each of the above concepts may be mapped using different solutions for the same problem. We will describe each different solution as a separate pattern. This approach allows us to clearly demonstrate the consequences of using a solution with respect to the general forces presented next. Mapping data types requires a larger effort [Kr95 ] and may be treated as a pattern language of its own. We will therefore leave it to future pattern mining work.

General Forces