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What is a relational database?
A relational database is a digital system that stores information in organised tables, much like spreadsheets, but with special features that make finding, sharing, and updating information safer, quicker, and less prone to errors.
Spreadsheet example: Managing a small business
Imagine your business keeps information about:
Products
Customers
Orders
With multiple spreadsheets:
- You might have one spreadsheet for customers, another for orders, and a third for products.
- If a customer places two orders, their information is copied into both order records.
- Errors can creep in—for example, spelling the customer’s name differently in different places.
Typical problems:
- Data gets duplicated.
- It’s hard to know which version of something is up-to-date.
- Finding or changing information in many places is time-consuming and error-prone.
How a relational database works
A relational database organises your information into connected tables:
Example tables
Customers
| Name | Address | ||
|---|---|---|---|
| 1 | Sarah Smith | London | s.smith@email.com |
| 2 | John Brown | Manchester | j.brown@email.com |
Orders
| CustomerID | ProductID | OrderDate | |
|---|---|---|---|
| 101 | 1 | A1 | 01/02/2023 |
| 102 | 1 | B1 | 15/03/2023 |
Products
| Name | Price | Stock | |
|---|---|---|---|
| A1 | Laptop | £799 | 23 |
| B2 | Printer | £249 | 15 |
- Customers table: Each customer appears once. Each has a unique ID.
- Orders table: Links to Customers by CustomerID, and to Products by ProductID.
- Products table: Each product has a unique ProductID.
Connections: Instead of copying all the customer details onto every order, you just record the CustomerID. The database “relates” the tables so you can always see which orders go with which customers and products.
Benefits over multiple spreadsheets
1. No double entry
Update a customer’s email address in one place, and it’s correct everywhere.
2. Accuracy and consistency
No typos or out-of-date info scattered in different worksheets.
3. Easy, powerful searching and reporting
Need a list of all orders for a specific customer? Or sales by product? The database retrieves this instantly—no need to hunt through files.
4. More secure, with better access control
You can control who can see or change different kinds of information.
5. Scalable
Databases handle much more data than spreadsheets without becoming slow or impossible to manage.
6. Collaboration
Multiple users can safely work with the data at the same time, without overwriting each other’s changes.
In Summary
A relational database:
- Keeps information organised, up-to-date, and connected.
- Reduces manual work, mistakes, and confusion.
- Makes it easy to get the information you want, fast.
Moving to a relational database is like replacing a filing cabinet full of scattered papers with a highly organised, smart digital assistant that never misplaces or duplicates anything!
Nick Ellis
AI and Innovation Lead