What it is
A workspace for learning SQL that needs nothing but a browser. It runs SQLite, the database engine used in phones and browsers, compiled to WebAssembly.
Three databases: an office supplies shop (customers, products, orders and order items), school scores (students, courses and scores), and an empty database for creating your own tables.
Twelve tasks from a first WHERE to joins across three tables and a subquery. "Check my query" compares the learner's result with the expected one, row by row. A hint and the solution are one click away, never shown unasked.
The schema of every table, with a click to insert a table or column name.
Safe for school use
Everything runs on the learner's device. Queries are never sent to a server, and nothing is stored.
A query that runs too long is stopped after a few seconds and the database is reset, so a mistake cannot freeze the tab.
No account, no cookies needed, no personal data asked for.
Sharing without storing
"Share" turns the dataset, the query and the open task into a link. The information sits in the part of the address after #, which browsers never send to a server. A teacher can prepare a starting query and post the link; a shared query is only run when the learner presses Run.
Ideas for class
Warm-up: everyone opens the shop database and runs
SELECT * FROM customersto read the table together.Pairs: work through the shop tasks; the first pair with all six solved explains task 5 (customers without orders) to the class.
Build your own: in the empty database, each group designs a table for something from school life (lending library, sports club) and writes three questions for another group.