A semantic object-oriented data access system

Lack of support for Entity-Relationship (E-R) semantics and the disconnect between object-oriented programming languages (OOPLs) and database languages remain key roadblocks to the effective use of object-orientation in information systems development. We present SOODAS, a Semantic Object-Oriented Data Access System that defines and manages the meta-data necessary to support E-R semantics and set level querying and provides related interface generation tools. SOODAS consists of five meta-classes. DomainObject and Relationship provide the capabilities needed to define and manage entities, attributes, relationships, external identifiers, and constraints. Together with the meta-class QueryNode, DomainObject provides an object-oriented, multi-entity querying capability. Queries can be arbitrarily complex and can include cycles and transitive closure. Persistence is provided by the meta-class, PermanentObject, of which DomainObject and Relationship are subclasses. The meta-class, DomainObjectInterface uses the meta-data in DomainObject and Relationship to generate a standard, re-usable interface for displaying and maintaining instances of any entity. Since SOODAS is implemented entirely in Smalltalk, it can be seamlessly integrated with any Smalltalk application. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.