7. Define bindings, role cardinalities and constraints
Define cardinality:
- a minimum and a maximum number of instances of a role type (with its object types instances) a relationship type instance can have.
- “View from the relationship”
- Example: Inheritance relationship:
- Superclass role type has a cardinality of 1,1 in an inheritance
- Subclass role type has a cardinality of 1..N to allow for any number of subclasses for an inheritance relationship.