What is a relational database?

The easiest way to understand a relational database is to compare it with a flat file database. A flat file database has just one table. An example is your Contacts database, which contains one table with fields for name, address, phone number, email address, etc.

Suppose you want to track events that your contacts have attended. With a flat file database, you would need to enter event details (dates, leader, fee) in every single record. Whenever you changed a detail, you'd have to make that change in every record.

A relational database is more powerful and easier to keep up-to-date. It lets you:

• Link two or more tables that store related information
• Save time when you update information that applies to multiple records
• Make your data more accurate and consistent

How to create a relational database:

Here's how you could create a relational database for Contacts and Events:

• Create a database with two tables: Contacts and Events.
• In the Contacts table, create fields for contact information plus Event Name.
• In the Events table, create fields for Event Name, date, description, leader, etc.
• The Event Name field is the common field in both tables. Just link the Event Name fields in the two tables to create a relational database.

When you add a new contact in your relational database, just enter the Event Name. The other event details, like description and date, are automatically filled in from the Events table. And if you set up a two-way relational database, a simple feat with an easy database, you can also call up an Events record to see contact information for the people who have signed up.

Examples of when to create a relational database

You can create a relational database to link:

• Sales, stock control and suppliers
• Music files and details about the artist
• Students and upcoming tasks and details
• Customers and products they've ordered