SQLZoo tutorial and assessment objectives
Try selected public learning objectives through original work tasks.
Reference: SQLZoo. Checked 2026-10-04.
Original operations cases using selected SQL topics; excludes window functions and external assessments.
These are original lessons, synthetic datasets and assessments. Skill Workbench is independent of the source provider.
Objective coverage
Nested SELECT
selected practice
Count a funnel honestly →SUM and COUNT
selected practice
Account for partial refunds →JOIN
selected practice
Account for partial refunds →NULL
selected practice
Flag inventory exceptions →Public objectives summarized. No source lessons, paid exercises or media reproduced.
Start the original mini-course →