DELETE in the right order in SQL
SQL interview exercise on Modifying Data, difficulty 2 of 3. Solve it in the editor beside a worked example; the tests run the moment you do.
Remove every cancelled order completely: its lines in order_items and the order itself. Foreign keys are enforced, so an order that still has lines cannot be deleted.
Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Progress is saved in your browser, and in your account if you sign in.