ch7

Question 1

what is data modeling

Answer 1

is formal way of representing data that are used and created by a business

Question 2

what is the one of the most common data modeling technique used in the industry

Answer 2

entity relationship diagramming

Question 3

(ERD)stand for

Answer 3

entity relationship diagram

Question 4

what is entity relationship diagram

Answer 4

is picture which shows the information that is created stored and used by business system

Question 5

what is the meaning of crow foot that closest to the chemical request

Answer 5

that an lca may make many chemical requast

Question 6

what is the meaning of the two bars closest to the lca

Answer 6

that the chemical request is made by exactly one lca

Question 7

what is the elemants of entity relationship diagram

Answer 7

entities
attributes
relationships

Question 8

what is entity in ERD

Answer 8

IS the building block for a data model

it is person place event or thing about which data is collected described in capital letters

Question 9

what should entities have

Answer 9

name

short dicribtion

Question 10

what is attribute

Answer 10

is some type of information that is captured about an entity

Question 11

mcq
attribute is descibed as
noun or verb

Answer 11

noun

Question 12

the attribute that serve as identifier are noted by ……….next to the attribute name

Answer 12

asterisk

Question 13

if we put the two attribute the same

what we should do

Answer 13

do concatenation +to be different from the other
we can find a field that make it different from the other
we can generate random number for it

Question 14

what is relationship in erd ?

Answer 14

are associtions between entities and they are shown by lines that connect the entities together

Question 15

what is the type of relationship

Answer 15

parent

child

Question 16

what is parent

Answer 16

the first entity in the relationship

Question 17

what is the child

Answer 17

the second entity in the relationship

Question 18

what is the attribute of relationship

Answer 18

should be active verbs
the top words read from parent to child
the bottom words read from child to parent

Question 19

what is the two prosperities of relationships?

Answer 19

cardinality

modality

Question 20

what is the cardinality

Answer 20

which is the ratio of parent instance to child instances

Question 21

what is the meaning of 1:1

Answer 21

relationship means that one instance of the parent entity is associated with on instance of child entity
bar near of the child entity and bar near to parent entity

Question 22

what is the meaning 1:N

Answer 22

one to many one parent entity to many child entity

Question 23

what is the meaning of M:N

Answer 23

many to many

Question 24

what is modality

Answer 24

which refers to whether or not an instance of child entity if the child entity can exist without parent entity

null or not null
page 198

Question 25

what is null meaning in the erd and not null

Answer 25

null that chemical can exist without the chemical request and not null that cannot be chemical request without chemical

Question 26

what is data dictionary

Answer 26

is in case tool is where the analyst goes to define or look up information about the entities attributes and relationships

Question 27

what is metadata

Answer 27

the information you see in the data dictionary | is anything that describes an entity attribute or relationship