relational databases and SQL

Question 1

what is a database

Answer 1

are structured , persistant collections of data

Question 2

where are databases used

Answer 2

schools - eg.
… learning platforms such as Google Classroom
…. management information systems such as SIMS or iSAMS
organisation/business use- eg
…. online calenders eg google calender
CRM softare ( customer relationship management)
personal use - eg
…. social media
….multiplayer games

Question 3

what are the data types in SQL language

Answer 3

• float ( number with a decimal point )
  -CHAR ( fixed-length string up to 8000 characters )
  -VARCHAR ( variable length string up to 8000 characters
• integer ( whole number )
• text ( variable length sting up to 2 GB of data
  date, time, DateTime (to store dates and times )

Question 4

what is a flat - file database

Answer 4

stores a single table of data inside a single text file
- they are also stored in a CSV format
- they are typically used in small/ trivial datasets

Question 5

what are the advantages of data bases when handling large data sets

Answer 5

• makes processing easier
• reduces storage requirements
• avoids redundancy

Question 6

what are the types of data bases

Answer 6

flat file database
-relational database

Question 7

what are the disadvantages of a flat file

Answer 7

• very inefficient as data is often duplicated
• difficult to query as data is consumed in one table
• suffer from inconsistencies between records

Question 8

what is a table

Answer 8

stores records and fields in an organised manner

Question 9

what is a record

Answer 9

set of data stored in a table,

Question 10

what is a field

Answer 10

one item of data , a column in a table

Question 11

what is a primary key

Answer 11

fieild containing unique values for all records

Question 12

what is a relational data base

Answer 12

have more than one related table
and eliminates data inconsistency and data redundancy

Question 13

what is a database management software