Record structure

Before setting up a database [database: a structured collection of records or data stored in a computer system ], the record structure must be decided to make best use of the memorymemory: Where a program or data is stored on a computer. and backing store [backing store: a computer's primary data store, ie the hard disk ], and to make searching and report creation easier.

For example, a car showroom wants to record details of the cars it sells. Before setting up the database, the following questions need to be answered:

1. What information is needed?
2. What validationvalidation: checking data entered against a predefined set of rules could there be?

With these questions answered, informed decisions can be made about the record structure. This is how it might begin:

Record structure

When designing a database it is important to choose the correct field type. This ensures that the data [data: information without context, eg a list of students with numbers beside their names is data, when it's made clear that those numbers represent their placing in a 100 metre race, the data becomes information ] stored is usable and it makes validation easier. For example, if the price paid for goods was stored in a text field, then the database wouldn’t be able to add each individual figure to produce a total.

Key fields

A database should always contain a key field.

The following are examples of key fields:

• car registration number
• National Insurance number
• your school's examination centre number
• your own examination candidate number

Storing data in tables

Databases store data in tables, a single database file can store many tables, queries and reports. In the example table below there are six columns (divided vertically) and four rows (divided horizontally), each column has a heading, eg Registration number.

A database in which all the data is stored in a single table is known as a flat file database.