Town Errands: learn SQL by running errands

Six errands around a tiny town. Type real SQL (SELECT, WHERE, ORDER BY, GROUP BY, JOIN); it runs in a small database inside this page. Nothing is uploaded and nothing is tracked.

SELECT col1, col2 FROM table
WHERE col = 'text' AND num > 3
ORDER BY num DESC LIMIT 5

SELECT col, COUNT(*), SUM(num)
FROM table GROUP BY col
HAVING COUNT(*) > 2

SELECT a.x, b.y FROM a
JOIN b ON a.b_id = b.id