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 language s remain key roadblocks to the effective use of object-orientation in infor mation systems development. We present SOODAS, a Semantic Object-Oriented D ata Access System that defines and manages the meta-data necessary to suppo rt E-R semantics and set level querying and provides related interface gene ration tools. SOODAS consists of five meta-classes. DomainObject and Relati onship provide the capabilities needed to define and manage entities, attri butes, relationships, external identifiers, and constraints. Together with the meta-class QueryNode, DomainObject provides an object-oriented, multi-e ntity querying capability. Queries can be arbitrarily complex and can inclu de cycles and transitive closure. Persistence is provided by the meta-class , PermanentObject, of which DomainObject and Relationship are subclasses. T he meta-class, DomainObjectInterface uses the meta-data in DomainObject and Relationship to generate a standard, re-usable interface for displaying an d maintaining instances of any entity. Since SOODAS is implemented entirely in Smalltalk, it can be seamlessly integrated with any Smalltalk applicati on. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.