Almost every application is backed by a database, and SQL is the language used to work with the relational databases that store most of the world's structured data. Learn it once here and reuse it across analyst, developer, cloud and DBA roles.
Interactive explainer
The Relational Model
Tables, rows, columns and keys — the foundation of SQL.
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Tables
One kind of thing.
A relational database stores data in tables (relations). Each table holds one kind of entity — Customers, Orders, Products — like a well-defined spreadsheet.
Check your understanding
1. What makes a database 'relational'?
2. What kind of language is SQL?
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What this path covers
- Relational Databases & SQL — tables, rows, columns and what SQL is.
- Design & Normalization — organising data to avoid redundancy.
- Keys & Relationships — primary and foreign keys.
- CRUD Operations — SELECT, INSERT, UPDATE, DELETE.
- JOINs & Aggregation — combining tables and summarising data.
- Indexes & Performance — making queries fast.
- Views & Stored Procedures — reusable, secure logic.
- Transactions & ACID — reliable, consistent changes.
- Database Security & Permissions — least privilege for data.
- Backup & Recovery — protecting against data loss.
- Introduction to NoSQL — when non-relational fits better.
Where this fits
Combine with Cloud Fundamentals and Linux Fundamentals, then rehearse with AI Interview™ and evidence it in your Career Passport™.
Start with Relational Databases & SQL.