LEsson 4

Question 1

is a data model that describes relationships among entities at the conceptual level with the help of ER diagrams.

Answer 1

Entity Relationship Model (ERM)

Question 2

is a diagram that depicts an entity relationship model’s entities, attributes, and relations.

Answer 2

Entity Relationship Diagram (ERD)

Question 3

An entity is represented in the ERD by a ____________-, also known as an __________ The name of the entity, a noun, is written in the center of the rectangle.

Answer 3

An entity is represented in the ERD by a rectangle, also known as an entity box. The name of the entity, a noun, is written in the center of the rectangle.

Question 4

The entity name is generally written in

Answer 4

capital letters

Question 5

A collection of similar entities is known as an

Answer 5

entity set.

Question 6

describe associations among data

Answer 6

Relationships

Question 7

The type of relationship between entities is called ___________-and is represented in an ERD by a _______________-.

Answer 7

The type of relationship between entities is called connectivity and is represented in an ERD by a line.

Question 8

Relationships are represented by a diamond connected to the related entities through a relationship line. The relationship name is written inside the diamond.

Answer 8

Chen Notation

Question 9

Entities are connected by lines, and symbols at either end describe the cardinality of the relationship between the entities.

Answer 9

Crow’s Foot Notation

Question 10

Each entity consists of a _____________ that describes characteristics of the entity.

Answer 10

set of attributes

Question 11

In the original Chen notation, attribute are represented by ___________and are connected to the entity rectangle with a line. Each oval contains the name of the attribute it represents.

Answer 11

ovals