Forename

Surname Form Subject Teacher Grade

Harry Smith A ICT Miss Bunce

A

Fiona Jones B History Mr Evans B

Harry Smith A History Mr Evans B

Jenny Fields B Art Miss Gold A

Harry Smith A Art Miss Cold A

Jenny Fields A ICT Miss Bunce

A

What is the problem with this flat file database?

Forename

Surname Form Subject Teacher Grade

Harry Smith A ICT Miss Bunce

A

Fiona Jones B History Mr Evans B

Harry Smith A History Mr Evans B

Jenny Fields B Art Miss Gold A

Harry Smith A Art Miss Cold A

Jenny Fields A ICT Miss Bunce

A

1. Data is duplicated – each exam entry requires the pupil data to be entered again

2. Data is inconsistent – mistakes are made3. Difficult to add an extra field

Large collection of data items stored in separate tables with

links between them

e.g. – driving school has students, lessons and lesson types – all linked by the lesson table

e.g. – driving school has students, lessons and lesson types – all linked by the lesson table

You can view all the related data together

Data independence – data and programs stored separately. You can add an extra table and it won’t affect the programs.

Data consistency – data is only stored once – no danger of it being updated in one place and not in another

No data redundancy – data is not duplicated unnecessarily

More information available to users - all information is stored centrally – not in separate departments

Ease of use – queries etc. Data integrity – validation ensures

data is as correct as possible Greater security – authorised users –

different access levels

Complex and costly to set up Needs greater knowledge to set up Users require more training If data used for a range of

applications – security and confidentiality issues arise

Database is made of records – each record has a structure containing fields.

Data type Description Example

Integer Whole number 4 or 5 or 818809

Currency Number representing a financial amount

£4.55 or $0.99

String Text or characters Josh or 41 Bridge Street

Date/time Dates or times in any format

15th May 2010 or 14:56 or 09/12/2009

Boolean Data which can only be one of two states

Yes or noTrue or false

Query – a method of searching a database for specific information

Report – printed output from a database for a specific purpose

Form – an interface to a table or group of linked tables for data entry

Import – data from an external data source brought into the database

Export – data from the database used for another purpose – e.g. Mail merge letter

Fields can be coded – e.g. M or F Database can have validation Each record has a key field which is

a unique identifier