⌘CodeQuest
← All courses

Databases & SQL

From spreadsheets to real databases: tables, keys, SQL queries, joins, normalisation, NoSQL, and which database language to pick for which job.

🟡 Intermediate7 lessons

  1. Lesson 1

    Lesson 1 — Why Databases Beat Spreadsheets

    What a database actually is, and why apps store data in one instead of a giant file.

    70

  2. Lesson 2

    Lesson 2 — Tables, Keys and Relationships

    Primary keys, foreign keys, and the one-to-many and many-to-many patterns behind every app.

    75

  3. Lesson 3

    Lesson 3 — SQL Basics: SELECT, WHERE, ORDER BY

    Ask a database questions in its own language and get exactly the rows you want.

    80

  4. Lesson 4

    Lesson 4 — Joins, GROUP BY and Aggregates

    Combine tables and turn thousands of rows into the one number a manager actually wants.

    90

  5. Lesson 5

    Lesson 5 — Normalisation, Constraints and Good Design

    1NF to 3NF, constraints, indexes — how to design a schema that stays correct as it grows.

    90

  6. Lesson 6

    Lesson 6 — SQL vs NoSQL: Choosing the Right Store

    Document, key-value, graph, column and time-series databases — and when each one wins.

    90

  7. Lesson 7

    Lesson 7 — Security, Performance and Real-World Practice

    Injection, least privilege, indexes, query plans, backups — the things that keep a live database safe and fast.

    100