QUESTION $27$

Using the above Crow's feet notation, a MOTHER$/$CHILD relationship would most likely be illustrated using on the MOTHER side and on the CHILD side.

a$.$ D$,$ B

b$.$ C$,$ C

c$.$ C$,$ A

d$.$ D$,$ A

QUESTION $28$

The attribute ADDRESS can be subdivided into street, city, state, and zip code. Similarly, the attribute PHONE$\_$NUMBER can be subdivided into area code and exchange

number. ADDRESS and PHONE$\_$NUMBER are

QUESTION $29$

A single$-$valued attribute is an attribute that can have only a single value. For example, a person can have only one Social Security number, only one mother and only one

address.

True

False

QUESTION $30$

True

False

QUESTION $31$

One of these definitions is incorrect:

a$.$ Regular entity: An entity that is existence$-$independent, that is$,$ it can exist apart from all of its related entities

b$.$ Derived attribute: An attribute that physically exists within the entity and is derived via an algorithm

c$.$ Composite identifier: In ER modeling, a key composed of more than one attribute

d$.$ Unary relationship: An ER term used to describe an association within an entity