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)