Treating enhanced entity relationship models in a declarative style

Abstract

In this paper we present an approach to represent schema information, application data and integrity constraints in form of a logic program. An information system is specified by an enhanced entity relationship (EER) model which is transformed by means of a one-to-one mapping into a set of ground facts. The application data corresponding to the schema is represented by ground facts called observations. In order to check whether the application data conforms to the given schema, a set of general integrity rules is defined which expresses the dependencies (functional, inclusion and exclusion dependencies) implied by the EER model. In order to check whether the application EER model is a valid EER model a meta EER model is defined. Any application EER diagram appears as an instance of the meta EER diagram and can be represented using observations. This way the same set of integrity constraints can be used to check the conformance between the application data and the application EER diagram, the meta EER diagram and the application EER diagram. Since the representation of the meta EER diagram is an instance of the meta EER diagram, the validity of the meta EER diagram can be checked as well. The resulting logic program is composed of the application data, the application schema, the meta schema, a general set of constraints plus optionally additional application specific constraints and deduction rules.