E-R Modeling

Entity is a _________

• Object of relation

• Present working model

• Thing in real world

• Model of relation

Who developed the E-R model?

• Codd

• Chen

• Date

• Bachman

What are the components of an E-R model?

• Entity

• Attributes

• Relationship

• All the above

The attribute name could be structured as an attribute consisting of first name, middle initial, and last name. This type of attribute is called

• Simple attribute

• Composite attribute

• Multi-valued attribute

• Derived attribute

The attribute AGE is calculated from DATE_OF_BIRTH. The attribute AGE is

• Single valued

• Multi valued

• Composite

• Derived

Which of the following can be a multivalued attribute?

• Phone_number

• Name

• Date of Birth

• Age

A weak entity set in an E-R diagram is an entity set that :

• has a primary key

• must be part of a one to many relationship set

• is not existence dependent on a dominant entity

• must not participate as owner in an identifying relationship with another entity set

E-R model uses which symbol for Weak entity

• Rectangle

• Diamond

• Double rectangle

• Dotted line

In an E-R model Oval represents

• Entity

• Attributes

• Relationships

• Cardinality

In an E-R model,an association among several entities is called

• Relationship

• Connectivity

• Cardinality

• Dependency