What is a relational database?

A relational database stores data in tables.

Each table is organised using rows and columns, and related tables can be connected using matching values.

Relational database meaning

A relational database keeps data structured, organised, and connected.

Instead of storing everything in one large table, related information is split into separate tables.

Sample tables

Here are two related tables in a relational database.

Customers table

Orders table

SQL query

This query joins Customers and Orders using customer_id.

SELECT
    c.customer_name,
    o.order_id,
    o.order_total
FROM Customers AS c
INNER JOIN Orders AS o
    ON c.customer_id = o.customer_id;

Output

Here is the result returned by the query.

Key takeaway