Structured Query Language (SQL)

1. Introduction

Data, such as a list of names, can be stored in a straightforward text file. But it has some major limitations in terms of searching and sorting the data.

An alternative to storing data directly in a file is to store it in a database.

A database is designed specifically to handle, sort, search and manipulate organised data.

A database is a collection of data or information which is held together in an organised or logical way.

Because of the high organisation of a database, data can be retreived, sorted and updated very efficiently.

Adding and retrieving information in a database is done using a special-purpose programming language called SQL.

The basic actions carried out on a database are

• Insert
• Update
• Delete
• Retreive
• Sort

The rest of this section will describe the parts that make up a database and how SQL is used to manipulate its data.