Solve it in your browser. Share your time. Come back next week. 113 challenges in rotation, picked deterministically each week — same challenge for everyone, no leaderboard gaming.
NULL means 'unknown', not zero. Find passengers whose age is NULL (unknown). Show name, pclass, fare, and a column called age_display that shows 'Unknown' when age is NULL, or the age value when it's known. Sort by fare descending. Limit t…
Past challenges are still solvable in the app. Each week's pick is deterministic, so anyone visiting that week sees the same challenge — fair time comparisons.
Practicing SQL works the way going to the gym works: a small, predictable habit beats heroic sprints. 15 minutes every Monday for a year is enough to clear most data-analyst SQL interviews. A scattered hour-here-and-there approach plateaus around month 2.
The Weekly Challenge is the ritual. Same time every week, fresh problem, no decision fatigue. Solve it, share it if you want to, come back Monday. The 200+ practice bank is here when you want unlimited; the weekly is for when you want a single committed rep.
SQL Quest's free tier covers Easy/Medium/Hard across the full bank, plus the AI Coach with a daily quota.
Open SQL Quest — Free ⚡Or: learn SQL from zero · interview prep hub · tutorials blog