SQL and databases

Question 1

structured data

Answer 1

fixed fields with data types

has metadata

Question 2

unstructured data

Answer 2

no discernible structure
no metadata
cannot be queried without being transformed

Question 3

data base

Answer 3

collection of information that is organised so it can be accessed, managed and updated

Question 4

field

Answer 4

column, single piece of data about an entity

Question 5

records

Answer 5

rows, the group of fields about a specific entity

Question 6

primary key

Answer 6

field that identifies each record uniquely

Question 7

foreign key

Answer 7

field in one table that is the primary key in another table, links the tables together

specified by a *

Question 8

why are data bases structured

Answer 8

unstructured information/data makes it hard to work with large datasets and to interpret

Question 9

flat file data base

Answer 9

data base with one table

Question 10

relational data base

Answer 10

has multiple tables that are connected through their key fields - foreign key

Question 11

why use relational data bases

Answer 11

• flat file data bases can lead to redundant data (repeats)

- inconsistencies likely to be introduced (as you have to manually add everything in so more likely to make mistakes)

Question 12

SQL

Answer 12

structured query language

Question 13

SQL select

Answer 13

SELECT Field(s)
FROM Table
WHERE Condition
ORDER BY Field ASC/DSC

Question 14

What are the album titles stored?

Answer 14

SELECT Title

FROM Albums

Question 15

What are the albums made after 2015, show the title and artist with newest first

Answer 15

SELECT Title, Artist
FROM Albums
WHERE Year > 2015
ORDER BY Year DESC

Question 16

What are the song names stored, how many streams did they have and what album are they in?

Answer 16

SELECT Name, Stream_Count, Title
FROM Albums, Songs
WHERE Albums.ID = Songs.ID

Question 17

Who is the teacher and what room are 12B/It in?

Answer 17

SELECT Teachers.Name, Room
FROM Teachers, Classes
WHERE Classes.Name = “12B/It” AND Teachers.TeacherCode = Classes.TeacherCode

Question 18

INSERT INTO

Answer 18

Adds a record to a table

INSERT INTO Table (fields)
VALUES (values)

Question 19

a null field

Answer 19

gaps, empty field in record

Question 20

DELETE FROM

Answer 20

removes record from table

DELETE FROM Table
WHERE Field = Value

Question 21

UPDATE

Answer 21

changes value or values in table

UPDATE table
SET Field = Value
WHERE condition

Question 22

Change price of protractor to £2.99

Answer 22

UPDATE Products
SET Price = “£2.99”
WHERE Name = “Protractor”