Database Management System: Unit II: Databases Design

Mapping Cardinality

Databases Design - Database Management System

Mapping Cardinality represents the number of entities to which another entity can be associated via a relationship set. The mapping cardinalities are used in representing the binary relationship sets.

Mapping Cardinality

Mapping Cardinality represents the number of entities to which another entity can be associated via a relationship set.

The mapping cardinalities are used in representing the binary relationship sets. Various types of mapping cardinalities are -

1) One to One: An entity A is associated with at least one entity on B and an entity B is associated with at one entity on A. This can be represented as,

2) One to Many: An entity in A is associated with any number of entities in B. An entity in B, however, can be associated with at most one entity in A.

3) Many to One: An entity in A is associated with at most one entity in B. An entity in B, however, can be associated with any number of entities in A.

4) Many to many:An entity in A is associated with any number (zero or more) of entities in B, and an entity in B is associated with any number (zero or more) of entities in A.



Database Management System: Unit II: Databases Design : Tag: : Databases Design - Database Management System - Mapping Cardinality