GCSE ICT - DatabasesA database is used to store a large amount of data in a structured way so that search queries can find the relevant information quickly. Flat file databases store all of the information on one flat file, very much like a huge spreadsheet. Relational databases link two or more flat files using key fields, i.e. the most important field in each table. Data updated in one flat file will automatically be updated in the other.

Before you design a database it is necessary to decide:

1.) What data you need.

2.) Whether you can validate this data.

Validation is when you purposefully limit the type of data that can be entered into a field. This helps to avoid any data entry errors. For example, if you have decided the key field is going to be someone’s National Insurance number, you know that it will consist of 9 characters and that the format will be like this:

Letter Letter Number Number Number Number Number Number letter

If someone were to enter a number into the first cell, for example, the entry will not be validated. You can prevent people from entering more than 9 characters by only providing 9 spaces on the data capture form – the paper form given to customers to enter their details.

Relational databases cross reference two flat files so that information doesn’t have to be entered twice. A company may receive a call from one of their members complaining about the non-delivery of a case of wine. The complaints form only requires the input of his unique ID (the contents of the key field e.g his membership number) in order to populate the electronic complaints form with personal details already held elsewhere. This saves time and data storage space.

ICT - DatabasesSome of the common features you will find in database software include the ability to:

– Insert and delete a field

– Enter and edit field contents

– Identify a unique key field

– View the database structure

– Create and develop charts and graphs based on data content. Certain fields can be selected to produce a single report.

– Insert headings, headers and footings

-Organise and select records

– Search and filter records according to selected criteria e.g. if requested it can show records of all customers living in Manchester.

– Mail merge. This involves extracting the contents of certain fields, e.g. name, address and postcode and transferring it across automatically to a new document. This can be done in bulk and enables an organisation to print envelopes, payslips, membership cards and letters with great efficiency.