Entity Types and Relationships There are many kinds of entity relationships in a database model. The relationships can be classified by the following things.
Cardinality: maximum and minimum Degree: binary, ternary, degree 4, and so forth Entity type: strong, weak, ID-dependent, and supertype/subtype What are these different types of classifications? Do they overlap, or do they each tell us something unique about the entity relationship? Why is it important to classify each of these types in an ERD (entity relationship diagram) model?