A method of mapping a relational database schema to an object oriented schema to have a co-existing relational database

摘要

A method of mapping a relational database schema to an object oriented schema to allow co-existence of the relational database with an object database comprises: (a) extracting the schema data from the relational database, including database tables, columns, special columns, primary keys, foreign keys, indexes and stored procedures and parameters; (b) enhancing the relational database schema by (i) mapping tables to classes, (ii) mapping columns to attributes, (iii) defining classes of set, array and dictionary collections based on primary key and index data, (iv) establishing relationships from the primary keys, foreign keys and columns having the same names and (v) defining relationship implementation based on heuristics by using the cardinality of the tables to define the cardinality of the relationship between the corresponding classes; (c) generating structural query language (SQL) code fragments to support collection operations from the information derived in step (b) and storing same for run-time access to the relational database and (d) storing in the object database a description of the classes and collections established in step (b) for use in runtime by an object oriented application whenever access to data in the relational database is required.