ER Model: Notation and Constructs
Chen notation for entity sets, weak entity sets, relationships and identifying relationships; the attribute kinds (simple, composite, multivalued, derived, key, partial key); relationship degree and role names; cardinality ratio versus participation and the (min, max) notation, which places its labels on the opposite side from the ratio; weak entities and their owners; specialization, generalization and aggregation; and why a ternary relationship is not three binary ones.
