SQLab

Learn

From zero to professional: every topic in plain language, with a live example and an exercise. Differences between PostgreSQL and MySQL are called out.

Start

Module 01

Basics

What a database is and how to ask a table for data

  1. 1What is a database?6 min
  2. 2Your first SELECT7 min
  3. 3WHERE: picking the rows you need8 min
  4. 4IN, BETWEEN, LIKE and NULL8 min
  5. 5Sorting, LIMIT and DISTINCT7 min

Module 02

Calculations

Functions, dates and counting by groups

  1. 6Expressions, functions and CASE9 min
  2. 7Working with dates7 min
  3. 8COUNT, SUM, AVG, MIN, MAX7 min
  4. 9GROUP BY and HAVING9 min

Module 03

Joining tables

Keys, relations and the kinds of JOIN

  1. 10Keys and relations7 min
  2. 11INNER JOIN9 min
  3. 12LEFT JOIN and rows without a match8 min
  4. 13Several tables and the self join8 min

Module 04

Advanced queries

Subqueries, CTEs and window functions

  1. 14Subqueries10 min
  2. 15UNION, INTERSECT, EXCEPT6 min
  3. 16WITH: named queries8 min
  4. 17Window functions11 min

Module 05

Creating and changing tables

Types, constraints, INSERT / UPDATE / DELETE and design

  1. 18CREATE TABLE: types and constraints10 min
  2. 19INSERT, UPDATE, DELETE8 min
  3. 20ALTER, DROP, TRUNCATE6 min
  4. 21Designing a database well9 min

Module 06

Going professional

Speed, reliability and security

  1. 22Indexes and EXPLAIN9 min
  2. 23Transactions and ACID9 min
  3. 24Views: saved queries6 min
  4. 25Functions, procedures and triggers9 min
  5. 26Users, privileges and backups7 min