Last updated: August 27, 2026.
Use the tutorial’s sample tables to practice read-only queries first. Start with a narrow SELECT, add filters, then introduce sorting or grouping.
Starter queries
SELECT OwnerID, OwnerFirstName, OwnerLastName
FROM AntiqueOwners
ORDER BY OwnerLastName, OwnerFirstName;
SELECT Item, AVG(Price) AS average_price
FROM Antiques
GROUP BY Item
ORDER BY Item;Safe practice workflow
| Step | Purpose |
|---|---|
| Read the table structure | Confirm column names, types, keys, and relationships. |
| Run SELECT first | Check which rows match before modifying data. |
| Use a transaction | Test INSERT, UPDATE, and DELETE and roll back when appropriate. |
| Add one clause at a time | Make errors easier to isolate. |
SQL dialects differ. Run examples in a disposable database that matches your intended engine.
