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Flashcards in Databases Deck (32)
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1
Q

What is a database?

A

a persistent store of organised data which allows data to be queried/interrogated.

2
Q

What does persistent store mean?

A

Once data is put into the database it is stored in non-volatile storage and can be accessed again later

3
Q

Give some examples of places which have databases

A

School, Doctors, Dentists, Online Shopping, Social Media

4
Q

What does DBMS stand for?

A

DataBase Management System

5
Q

Why is the DBMS desirable?

A
  • its a standard way of accessing data
  • it gives security
  • it can have multi user access
  • there is data maintenance
6
Q

What is a flat file database?

A

a database that only has one table

7
Q

What is a relational database?

A

a database with more than one table

8
Q

What is data redundancy?

A

when data is duplicated

9
Q

What are some features of the DBMS?

A
  • A command language
  • a data manipulation language
  • a data dictionary
  • provides security
  • the ability to view from different viewpoints
10
Q

What does each table/entitity have?

A

its own unique identifier (primary key)

11
Q

What is a record?

A

A row on the table

12
Q

What is a field?

A

a column of the table

13
Q

What is a form?

A

An input screen allowing chosen data items to be displayed and edited
uses texboxes/drop down lists/checkboxes etc…
when edited, the changes are updated in the
database

14
Q

What is a query?

A

used to search and filter in a database

15
Q

What is a Report?

A

An output of the data in a database

a snapshot of the data at a given time/when printed of specified fields/Laid out in a specified format

16
Q

What is a Module?

A

a pre-written program in database software

17
Q

What does using the logic operator AND do in a query?

A

makes sure both criteria are met

18
Q

What does using the logic operator OR do in a query?

A

makes sure one of both of the criteria are met

19
Q

What language are queries written in?

A

SQL

20
Q

What does the presence check do?

A

checks if data has been entered into the field

21
Q

What does to range checks do?

A

ensures that numerical data is between a particular range

22
Q

What does a length check do?

A

if the data is too short or too long it would not be valid

23
Q

What does the format check do?

A

ensures the data is in a particular format

24
Q

What does the lookup check do?

A

looks up the data and checks it exists

25
Q

What does check digit do?

A

the computer performs a calculation to check the numbers are right

26
Q

Why is data separated from applications?

A

gives the user a greater flexibility in how the data can be used.

27
Q

Why is a foreign key needed?

A

to link tables, allows you to retrieve data from another a table and avoids you re-writing data everytime. avoids data redundancy

28
Q

What is an entity?

A

A real world object which data is stored about in a database. They are the tables.

29
Q

What different relationships between tables can there be?

A

one-to-many
many-to-many
one-to-one

30
Q

What is the DBMS?

A
  • Database Management System/Used to manage
    the database
  • May use SQL/allows database to be queried
  • Provides facilities for creating tables/inserting
    data
  • Allows data structure to be independent of the
    program
  • Allows relationships to be created between
    tables
  • Provides security features/levels of access
31
Q

What is HTML?

A
  • HyperText Mark-up Language
  • Text file containing the text to be displayed uses tags which indicate how to display it location of pictures/other elements to include and hyperlinks to other locations/URLS
32
Q

Why is HTML used?

A

Because it is an open/accepted standard data will display correctly on all browsers which conform to the standard