1. E-R Models Are Expressed Using a Single Standardized Set of Universally Accepted Symbols

IT 214

Quiz 3

Quiz

TRUE/FALSE

1.  E-R models are expressed using a single standardized set of universally accepted symbols.

2.  An entity is something in the users’ work environment that the users want to track.

3.  Entities of a given type are grouped into entity classes.

4.  Relationships do not have attributes.

5.  Relationship’s minimum cardinality indicates whether or not an entity must be involved in the relationship.

6.  Relationships among instances of a single entity class are called redundant relationships.

7.  A weak entity is an entity that cannot exist in the database without (and is logically dependent upon) another type of entity also existing in the database.

8.  All weak entities must have a minimum cardinality of 1 on the entity on which it depends.

9.  Inheritance in a generalization hierarchy means that the supertype entity inherits all the attributes of the subtype entity.

10.  UML is intended for modeling and designing object-oriented programs and applications.

MULTIPLE CHOICE

11.  An equivalent term for “attributes” is ______.

a.) identifiers

b.) properties

c.) entities

d.) instances

e.)  composites

12.  An identifier may be:

a.) composite

b.) unique

c.) a single attribute

d.) nonunique

e.)  all of the above

13.  A composite attribute is an attribute that:

a.) is multi-valued

b.) describes a characteristic of the relationship

c.) consists of a group of attributes

d.)  is calculated at run-time

e.)  is an identifier

14.  For a relationship to be considered a binary relationship it must satisfy which of the following conditions?

a.) it must involve exactly two entity classes

b.) it must have a maximum cardinality of 1:1

c.) it must have a maximum cardinality of 1:N

d.) both a and b

f.)  both a and c

15.  Supertype / subtype entities are said to have a(n) what kind of ______relationship?

a.) HAS-A

b.) IS-A

c.) recursive

d.) redundant

e.)  multi-valued