System and method for efficient relational query generation and tuple-to- object translation in an object-relational gateway supporting class inheritance

摘要

An object-relational database gateway for use in a computing environment having a relational database management system (RDBMS) is disclosed. Object-oriented objects in the computing environment conform to a class inheritance hierarchy defined by an object-oriented schema. The gateway includes a query generator to generate from an object- oriented query a set of relational queries. The object-oriented query identifies one or more target objects of a target class which are desired to be constructed. The set of relational queries, when processed, enable the RDBMS to retrieve tuples required to initialize base attributes of the target objects that are defined by the target class and by any super- classes and sub-classes of the target class. The gateway also includes a tuple-to-object translator to translate the tuples to object-oriented objects consistent with the class inheritance hierarchy.