Mapping Objects to Tables A Pattern Language
Wolfgang Keller · 1997
Mapping Objects to Tables is a problem that has occurred as long as people want to program in an object oriented language but have to use relational instead of object oriented databases for some reasons. Mapping Objects to Tables is only one family of problems that occurs in object/relational access layers. The whole context of object/relational access layers has been described by many authors (see [Bro+96, Col+96]) and is subject of our own future work. Introduction 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: . Aggregation, . inheritance and polymorphism, . associations between class...