Writing a good puzzle
- Ask a question a real analyst might ask: revenue by something, customers who did or did not do something, a top-N list.
- Name the columns you expect, since the grader compares column names as well as values.
- Say whether row order matters. If it does, the solver needs an ORDER BY.
- Give a hint that nudges without giving the answer away.
Submissions are reviewed before they appear, usually within a day or two.