Occasionally one sees an entity-relationship diagram (ERD) having an unusual characteristic. The unusual element is an entity (or more than one) that seems to have a relationship with every other ...

In building a logical data model, some entities are considered strong, other entities are considered weak. Strong entities are the most foundational elements within a nascent Entity-Relationship ...

Maths, Computing and Physics are all entity occurrences within the Subject entity. An entity-occurrence diagram shows the relationships between occurrences of a particular entity.