SQL Lessons

Master SQL from foundational SELECT statements through joins, grouping, schema design, security and vendor references.

Code preview

sql

SELECT name, COUNT(*) AS orders
FROM customers
JOIN orders USING (customer_id)
GROUP BY name;

●Customer order totals

74 lessons across 7 sections. Every example runs directly in your browser — edit the code and press Run.

Topics covered

SELECT queriesJoinsAggregatesTransactions