Databases

Question 1

Databases

Answer 1

an organized collection of data that can be accessed, managed, and updated

Question 2

relational database

Answer 2

a particular type of database built upon the relational model of data

Question 3

Data in a relational database can be accessed and reassembled in many different ways without having to reorganize the data.

Answer 3

Each entity is stored in a table.
Columns are called attributes
Rows represent individual records.
Rows represent individual records and consist of many attributes organized using columns.

Question 4

(R)DBMS

Answer 4

Relational Database Management System

Question 5

Relational Database Management System

Answer 5

is a software application designed to manage a database. It has four basic functions

Question 6

four basic functions Relational Database Management System

Answer 6

Data Definition
Data Storage
Data Retrieval
Administration

Question 7

RDBMSs include databases like

Answer 7

Oracle, Microsoft Sql Server, PostgreSQL, MySql, are relational, and are commonly called SQL Databases.

Question 8

NoSQL Databases are

Answer 8

do not use a relational structure, instead they structure data specific to the problem they are designed to solve.

Question 9

NoSQL databases include

Answer 9

MongoDB, Cassandra, Google BigTable, HBase, DynamoDB, and Firebase

Question 10

entity

Answer 10

a set of data being stored a table

Question 11

Table

Answer 11

defines a set of data elements and the structure to store them. Tables are structured into columns and rows.

Question 12

Columns

Answer 12

attributes of a table and define the name and data type. A table has a set number of defined columns

Question 13

Rows

Answer 13

the data being stored. A table has an unlimited number or rows.

Question 14

Cell

Answer 14

the location where a column and row intersect, and is used to refer to a specific value or row of data (entity).

Question 15

SQL

Answer 15

Structured Query Language

Question 16

Structured Query Language

Answer 16

a language that lets you access and manipulate databases

Question 17

ANSI-SQL

Answer 17

A standard that databases must follow to be considered a SQL Database.

All SQL databases support the ANSI-SQL language, however, most databases extend it with their own proprietary additions.

Question 18

Character Data Types

Answer 18

character, varying character, text based data

Question 19

char(#)

Answer 19

character. # defined the length of the data.

Question 20

varchar(#)

Answer 20

varying character. # defined the length of the data.

Question 21

text

Answer 21

text based data that is not limited by a predefined size

Question 22

Numeric Data Types

Answer 22

int, bigint, decimal(p, s)

Question 23

int

Answer 23

integer - similar to Java’s int

Question 24

bigint

Answer 24

Big Integer, similar to Java’s long

Question 25

decimal(p, s)

Answer 25

floating point numbers, similar to Java’s double or BigDecimal

Question 26

p - precision

Answer 26

the total number of digits being stored

1234.567 has a precision of 7

Question 27

s - scale

Answer 27

number of digits to the right of the decimal point

1234.567 has a scale of 3

Question 28

boolean

Answer 28

true/false

Not the same in all SQL databases
Mysql - tinyint(1)
PostgreSQL / Oracle - boolean
MS Sql - bit

Question 29

DATE

Answer 29

yyyy-mm-dd

Question 30

TIME

Answer 30

hh:mm:ss

Question 31

TIMESTAMP / DATETIME

Answer 31

yyyy-mm-dd hh:mm:ss

Question 32

Structured Query Language (SQL)

Answer 32

A declarative programming language used to manage a database and its data. A declarative programming language specifics what actions should be performed rather than how to perform those actions.

Question 33

DDL

Answer 33

Data Definition Language

Question 34

Data Definition Language

Answer 34

defines the structure of the data

Question 35

DML == SQL

Answer 35

Data Manipulation Language

Question 36

Data Manipulation Language

Answer 36

query and modify the data

Question 37

DCL

Answer 37

Data Control Language

Question 38

Data Control Language

Answer 38

used to administer the database

Question 39

SELECT

Answer 39

clause indicates what columns that you want to get from a database table

Question 40

FROM

Answer 40

clauses indicates which table(s) to retrieve the data from.

SELECT name, population FROM country;

Question 41

WHERE

Answer 41

clause is used to filter the rows returned in the results using conditional clauses.

SELECT name, population
FROM country
WHERE population > 100000000;