Test 1

Question 1

Relationships

Answer 1

One to one
One to many
Many to many

Question 2

Connectivity vs cardinality

Answer 2

Co.- describes the relationship classification

Card.- expresses min.&max. # of entity occurrences associated with one occurrence of related entity

Question 3

DIKW hierarchy

Answer 3

Data:raw
Information : data in context
Knowledge: application of data
Wisdom: evaluated understanding

Question 4

What is stored ?

Answer 4

End-user data - raw facts that are of interest to the user

Metadata - data about data - names of fields and tables in which data are stored

Question 5

Parent and child

Answer 5

Relationship b/w tables the table whose PK is being referenced is the parent table. The table referencing the PK w/ a foreign K is the child table.

Question 6

Altering tables

Add , drop & modify

Answer 6

Add column 
Add column_name datatype options
Modify changes the column characteristic 
Modify (column_name[options])
Drop deletes table/column 
Drop column column_name

Question 7

Data modeling

Answer 7

Graphical abstraction of real world

Notation: crows notation

Question 8

Entity vs attribute

Answer 8

En. - is an object about which data will be stored; it is distinct from other objects
At.- is a characteristic of an entity

Question 9

Relationship participation

Answer 9

Op. - one entity occurrence doesn’t require corresponding entity occurrence in particular relationship
Mp.- one entity occurrence corresponding entity occurrence in particular relationship

Question 10

Primary key
Composition key
Candidate key

Answer 10

PK- an attribute of attributes that uniquely identifies any given row
Ck - FK is a key composed of more than 1 attribute
Cand. Key- is any field that can be used as a PK

Question 11

Create table
Unique
Check
Default

Answer 11

,=,>=,<=,IN(values)
Unique- means that there can be no duplicate values in this field
Check- can be used to require values in certain field to meet specific criteria
Default- can be used to assign a default value to a field

Question 12

Classification

Answer 12

Multiuser vs single user
Centralized vs distributed
Operational vs analytical

Question 13

Referential integrity

Answer 13

Foreign K ensures the condition in which every reference to a row in a parent entity by a row in child entity is valid
A child table cannot reference a nonexistent parent
A parent cannot be deleted with a reference in a child table.

Question 14

SQL

Answer 14

Structured query language
SQL functions fit 2 categories
Data def. Lang. & manipulation Lang.

Question 15

Relational model

Answer 15

Entities- table
Attributes- fields
Instances-rows
Relationship - primary &foreign key

Question 16

Syntax notation 
[]
|
{}
Aa
_
...
...,

Answer 16

[]- used to enclose option items 
| used to separate items 
... indicate items that may be repeated 
.., repeated but separated by a comma 
{} item grouping 
Aa- items specified by the end user 
_ default options

Question 17

Issue w/ unstructured data (5)

Answer 17

Data inconsistencies 
Time
Structural dependence
Data redundancy 
Data anomalies

Question 18

Relationship

Answer 18

Describes an association b/w entities

Question 19

Creating databases

Answer 19

Create a database structure

Create a table that will store end-user data

Question 20

Schema

Answer 20

Group of database objects that are related to each other

Question 21

Data types (9)

Answer 21

Number
Char.
Varchar. 
Date
Timestamp 
Float 
Double 
Real
Precision

Question 22

Database management system (DBMS)

Answer 22

Electronic filling cabinet

Collection of programs that manages data, controls access, and maintains data integrity

Question 23

Entity integrity

Answer 23

Satisfied when each row in a table has its own unique identity
2 requirements
Each value in the PK must be require
No PK value can be null

Question 24

Client server model

Answer 24

Client - software program designed to send requests to a server.
Server- software program design to handle requests from a client

Question 25

Database

Answer 25

Essential for managing data related to customers, products transactions, & other items and events that are of importance to running a business

Question 26

Business rule

Answer 26

Is a brief unambiguous statement of a policy, procedure, or principle.

Question 27

Not Null

Answer 27

When added it can't be left blank 
Relationships SQL: 
Identifying foreign keys 
Determining if FK should be null or not 
Optional should have not null 
Mandatory should not have null values