Courses teach syntax, not investigation.
Legacy tools, disconnected examples, no real datasets. People finish having technically "done SQL" and still cannot write a query that answers a real question.
A SQL detective game with a real course behind it
54 guided cases across five detective ranks, taking you from your first SELECT to window functions. Real data, real queries, straight in the browser.
SQL education has been broken for a long time
"I know some SQL" is not confident SQL.
There is a wide gap between writing a basic SELECT and knowing how to actually interrogate data. Most platforms stop long before they bridge it.
Nothing teaches like a real problem.
The moments that move the needle are always the same shape: real data, a real question, and no choice but to work it out. That is the whole design brief.
See it in action
One case, start to finish
No videos. No multiple choice. You get a briefing, a real database and an empty editor. This is Case 001, and it is free.
Case 001
The Missing Donut
Free1The briefing
Chief Inspector Fox
Someone took the last donut. Our witness saw the culprit leave at 22:10, and whoever did it has no alibi. Find me a name.
2The evidence
suspects·nameleft_atalibi5 rows
3Your query
query.sql
1SELECT name, left_at, alibi
2FROM suspects
3WHERE alibi IS NULL
4AND left_at = '22:10';
4The result
Hit Run to see
what comes back.
what comes back.
That is the loop, 54 times over, getting harder every rank. The SQL above is real, and on QueryCase it runs against a real database inside your browser tab.
What is actually in it
Everything behind the login
Most SQL games are one puzzle. This is a path: five ranks that carry you from your first SELECT to window functions, drilled and exam-gated the whole way.
54
Guided cases
12
Drills
4
Rank exams
4
Investigations
7
Real datasets
The five ranks
Each rank teaches a band of SQL, drills it, then makes you pass an exam to move up.
Recruit
Where everyone startsYour very first SELECT, running in the browser before you even make an account.
Free, no signup
Rookie Detective
BeginnerFreeSingle-table basics: find it, filter it, sort it, count it.
SELECT · WHERE · AND / OR · IN · BETWEEN · LIKE · ORDER BY · LIMIT · COUNT
8 cases · 2 drills · graduation exam
Detective
IntermediateSingle-table mastery: aggregates, NULLs, text handling and type conversion.
COUNT / SUM / AVG / MIN / MAX · GROUP BY · HAVING · DISTINCT · IS NULL · COALESCE · UPPER / LOWER / SUBSTR / TRIM · CAST
18 cases · 4 drills · graduation exam
Senior Detective
AdvancedMulti-table SQL and real logic: dates, conditionals, subqueries, joins, set operations and CTEs.
JOINs (INNER / LEFT / anti / 3-table) · CASE WHEN · subqueries (scalar, IN, EXISTS, derived) · UNION / INTERSECT / EXCEPT · WITH (CTEs) · date maths
21 cases · 5 drills · graduation exam
Chief Detective
ExpertWindow functions, and capstone cases that combine everything you have learned.
ROW_NUMBER · RANK / DENSE_RANK · SUM() OVER · LAG / LEAD · PARTITION BY
7 cases · 1 drill · final exam + certificate
Beyond the path
The ladder is the spine. These are the reasons people stay.
Investigations
Timed, open-ended cases with no hand-holding. You get the evidence and a suspect list, and you have to actually work it out. The dataset reshuffles each attempt, so you cannot memorise the answer.
- The Louvre Affair
- Ghost Streams
- The Kanto Report
The Sandbox
Seven real datasets you can just query, 44 tables between them. No cases, no XP, no CSV download and no Postgres to install. Ask your own questions, and JOIN across datasets if you want to.
- IMDb Ratings
- Metro Crime
- Spotify Wrapped
- NBA 2024-25
- Steam games
- Pokémon
- TechCart
Career Hub
For when the goal is a job. Company-style SQL interview questions in a real editor with a worked solution, a rapid-fire multiple choice bank, and a guide to what each data role actually does.
- 15 interview questions
- 400 MCQ Quickfire
- Data roles guide
Every bit of SQL you will learn
The complete surface, start to finish. Standard SQL, so it transfers straight to PostgreSQL, MySQL, SQLite, BigQuery, Snowflake and Redshift.
- SELECT
- WHERE
- AND / OR
- IN
- BETWEEN
- LIKE
- ORDER BY
- LIMIT
- AS
- COUNT
- SUM
- AVG
- MIN
- MAX
- GROUP BY
- HAVING
- DISTINCT
- ROUND
- IS NULL
- COALESCE
- UPPER
- LOWER
- SUBSTR
- LENGTH
- TRIM
- REPLACE
- CONCAT
- CAST
- INTERVAL
- CURRENT_DATE
- DATEDIFF
- DATE_TRUNC
- CASE WHEN
- Subqueries
- EXISTS
- INNER JOIN
- LEFT JOIN
- Anti-joins
- UNION
- INTERSECT
- EXCEPT
- CTEs (WITH)
- ROW_NUMBER
- RANK
- DENSE_RANK
- SUM() OVER
- LAG
- LEAD
- PARTITION BY
The Recruit case and the whole Rookie rank are free, and you can solve your first case before making an account.
Start your first case →Behind the badge
Why QueryCase exists
I'm Conor. I've spent years working with data at companies ranging from a 70s retailer finding its feet in the cloud to a cybersecurity platform with 7 million users.
Every time I learned something genuinely useful in SQL, it was because I was handed a real problem and had to work it out. Never from a tutorial.
QueryCase is that experience, rebuilt as something you can actually learn from: real datasets, real questions, and a path that keeps going long after the basics.