SQL from Scratch: Query Real Data

Daniel academyInstructor: Daniel academy·beginner·Data

This course is for people who have never written a query and want the skill that sits under every analyst, backend, and data role: SQL. You will not memorize syntax from slides. From the first lesson you query a small coffee-shop database, tables of products, categories, customers, and orders, and the trainer runs your query on a real SQLite engine and checks the rows it returns. You move from a plain SELECT to filtering, sorting, aggregation, and joins across tables, the same steps a working analyst takes to answer a real question. By the end you can read a question in plain words, turn it into a query, and trust the answer, on your own data. Everything runs in your browser.

SELECT c.name,
       COUNT(o.id)  AS orders,
       SUM(o.total) AS revenue
FROM customers AS c
JOIN orders    AS o ON o.customer_id = c.id
WHERE o.created_at >= DATE('now', '-30 days')
GROUP BY c.name
HAVING SUM(o.total) > 1000
ORDER BY revenue DESC
LIMIT 10;