Draw ERD for Online Examination System – IGNOU MCA Assignment 2014 – 15

By | July 23, 2014

 MASTER OF COMPUTER APPLICATIONS
Course Code : MCS-014
Course Title : Systems Analysis and Design
Assignment Number : MCA(1)/014/Assign/13
Assignment 2013

ER Diagram

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
entity.

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.

Figure:- ERD

ERD_Online_Examination

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