MASTER OF COMPUTER APPLICATIONS
Course Code : MCS-014
Course Title : Systems Analysis and Design
Assignment Number : MCA(1)/014/Assign/13
Notations for the components of ERD:
Entities: An entity is something about which the business needs to store data. An entity is a class of persons, places, objects, events or concepts about which we need to capture and store data. An entity instance is a single occurrence of an
Attribute: An attribute is a descriptive property or characteristic of an entity. Synonyms include element, property and field.A compound attribute is one that actually consists of other attributes. It is also known as a composite attribute. An attribute “Address” is the example of compound attribute as shown in the following illustration
Relationships: A relationship is a natural business association that exists between one or more entities. The relationship may represent an event that links the entities.
Cardinality: defines the minimum and maximum number of occurrences of one entity that may be related to a single occurrence of the other entity. Because all relationships are bidirectional, cardinality must be defined in both directions for every relationship.
Draw ERD for Online Examination System. Make necessary assumptions.