Drill 5: Trade-off — Changing data safely

BEGIN;

INSERT INTO lessons (id, course_slug, title, minutes, level)
VALUES (11, 'sql', 'Transactions', 16, 'Advanced');

UPDATE lessons
SET minutes = minutes + 2
WHERE course_slug = 'sql';

SELECT id, title, minutes
FROM lessons
WHERE course_slug = 'sql';

ROLLBACK;