ERD Pre-Test

In an Entity-Relationship Diagram Rectangles represents:

• Entity sets

• Attributes

• Database

• Tables

The Primary key must be:

• Non Null

• Unique

• either a or b

• both a and b

The attribute that can be divided into other attributes is called:

• Simple Attribute

• Composite Attribute

• Multi-valued Attribute

• Derived Attribute

In an Entity-Relationship Diagram “Ellipses” or "oval" represents:

• Attributes

• Weak entity set

• Relationship sets

• Primary key

In an Entity-Relationship Diagram “Diamonds” represents:

• Attributes

• Weak entity set

• Relationship sets

• Multi-valued attributes

An entity in A is associated with at most one entity in B, and an entity in B is associated with at most one entity in A.

This is called as:

• One-to-many

• One-to-one

• Many-to-many

• Many-to-one

An entity in A is associated with at most one entity in B. An entity in B, however, can be associated with any number (zero or more) of entities in A.

• One-to-many

• One-to-one

• Many-to-many

• Many-to-one

Entity employee have attributes ID, CITY, and NAME .

Which one of this can be considered as primary key ?

• NAME

• ID

• CITY

• ID, CITY

Properties that describe the characteristics of entities are called:

• entities

• attributes

• identifiers

• relationships

In an E-R diagram attributes are represented by:

• rectangle

• diamond

• square

• ellipse or oval