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@inproceedings{DBLP:conf/er/Flory79,
author = {Andr{\'e} Flory},
editor = {Peter P. Chen},
title = {An Approach to Designing an Entity-Relationship Schema (Abstract)},
booktitle = {Entity-Relationship Approach to Systems Analysis and Design.
Proc. 1st International Conference on the Entity-Relationship
Approach},
publisher = {North-Holland},
year = {1979},
isbn = {0-444-85487-8},
pages = {143-144},
ee = {db/conf/er/Flory79.html},
crossref = {DBLP:conf/er/79},
bibsource = {DBLP, http://dblp.uni-trier.de}
}
BibTeX
The purpose of any data model is to allow the user of the model to describe and manipulate those objects in the real world that he intends to store in the data base. In the entity-relationship model this description is qiven by three basic concepts: entity-type, association-type between entity types (relationships) and characteristics (attributes) of entity types or association types.
It is also important to notice that it is fundamental to give directions as to the way the designer must use the concepts of the model to represent the real world and no many attempts have been done in this domain.
The aim of PP CHEN is to show that the entity-relationship model can be used as a basis for unification of different views of data and especially between the network model and the relational model. So the entity-relationship model can be seen as a super model of the relational model.
We first discuss the semantics of relations in the relational model and we show that a relation can be only used to model an entity type or an association type.
It is necessary to specify relations only in terms of attributes to assume that the universal relation exists.
The concept of functional dependency, which is the most important element when we consider how to group attributes to form entity type, is used to define