Mapping Cardinalities using E-R Diagrams

• One-to-One Mapping Cardinalities

• One-to-Many Mapping Cardinalities

• Many-to-One Mapping Cardinalities

• Many-to-Many:

• Weak Entity Set: A Entity Set without a Primary Key

There is a strong entity set and a weak entity set in the above diagram.

• Strong Entity Set: A Entity Set with a Primary Key

Reference :

Mapping Cardinalities Using E-R Diagram In Database.