An approach to href="module.php?name=Lexikon&file=search&eid=1&query=data modelling">data modelling proposed by P. Chen in 1976. The model says that you divide your database in two logical parts, entities (e.g. "customer", "product") and relations ("buys", "pays for"). Entity-relationship diagrams can be used to represent a model. ["The entity-relationship model: toward a unified view of data", P.P. Chen, ACM Transactions on Database Systems 1:1 pp 9-36, 1976]. (1998-03-20)