Learn SQL, the language behind almost every app that stores data. Using SQLite and a school library database, you go from your first SELECT to joins, subqueries, table design, indexes and safe queries from Python, and finish by building a database for a school club.
Lesson 1 is free to try. The other 15 lessons in SQL and databases are for schools on RudimentaryLabs.
What a database is, and how to pick out, filter and sort exactly the rows you want.
Turning many rows into totals, averages and per-group summaries.
How keys connect tables, and how joins put the pieces back together in one result.
Adding, changing and deleting rows safely, creating your own tables, and designing them well.
Harder ideas for older learners (subqueries, indexes and SQL injection) and a final project.