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Databases

A DATABASE is a structured collection of data that allows people to extract information in a way that meets their needs. The data can include text, numbers, pictures: and anything that can be stored in a computer. Databases are very useful in preventing data problems from occurring because:

• data is only stored once – no data duplication

• if any changes or additions are made it only has to be done once – the data is consistent

• the same data is used by everyone.

What are databases used for?

To store information about people, for example:

• patients in a hospital

• students at a school.

To store information about things, for example:

• cars to be sold

• books in a library.

To store information about events, for example:

• hotel bookings

• results of races

The structure of a database Inside a database, data is stored in TABLES, which consists of many RECORDS and each record consists of several FIELDS.

In order to be sure that each record can be found easily and to prevent more than one copy of the same record being kept, each record includes a PRIMARY KEY field.

Practical use of a database

They store data and provide facilities (tools) to search for specific records in a given set of data. They store special information used to manage the data.

Databases are used just about everywhere including banks, retail, websites and warehouses.