Learn data skills by solving mysteries
The most fun you'll have with a dataset. Detective games with real courses behind them: interrogate the database in the SQL Precinct or audit the books in the Excel Bureau, right in your browser. No prior experience needed.
THE SQL COURSE · THE PRECINCT
Learn SQL by interrogating the database
A SQL detective game with a real course behind it.
Question witnesses, cross-reference alibis and follow the money, all in SQL against a real database. Every concept from your first SELECT to window functions arrives inside a case that needs it.
-- Who opened the vault after closing time? SELECT name, entered_at FROM keycard_logs WHERE door = 'vault' AND entered_at > '22:00';
| name | entered_at |
|---|---|
| V. Ashcombe | 23:47 |
THE SQL CASE RUNNER
THE EXCEL COURSE · THE BUREAU
Learn Excel by auditing the ledger
An Excel detective game with a real course behind it.
Work fraud cases on a real spreadsheet engine: lookups that walk tables, text forensics that catch padded invoices, conditional formatting that lights up the double payment. The Bureau checks every figure against the evidence.
| A | B | C | D | |
|---|---|---|---|---|
| 1 | Invoice | Payee | Amount | Times paid |
| 2 | INV-2041 | Meridian Ltd | 480.00 | 2 |
| 3 | INV-2042 | Harbour & Co | 312.50 | 1 |
| 4 | INV-2043 | Meridian Ltd | 480.00 | 2 |
| 5 | INV-2044 | Kestrel Print | 95.20 | 1 |
| 6 | INV-2045 | Aldgate Fuel | 218.40 | 1 |
| 7 | INV-2046 | Bexley Signs | 75.00 | 1 |
| 8 | INV-2047 | Corvid Media | 1,240.00 | 1 |
| 9 | INV-2048 | Dray & Sons | 88.60 | 1 |
THE EXCEL ENGINE
THE GAME LAYER
Progress like a game, because it is one
Every closed case pays out XP, the victory screen rolls the numbers, and a daily streak gives you a reason to come back to the desk.
Each rank ends in a hands-on exam on fresh data, a boss fight. Pass it and the promotion is yours: four detective ranks in SQL, four examiner ranks in Excel.
Ranks are only the start. Special investigations and interview sets unlock collectible titles like Detective Pikachu, The Conductor and Diamond Hands, worn next to your name across the site.
Every rank exam mints a shareable certificate with its own verification code.
YOUR DESK CARD
What detectives actually say
I know basic SQL and honestly I did not understand window functions and some advanced concepts until I started querying in QueryCase. You have put all the concepts up in a structured manner.
This is my first approach to SQL in my life, and it is very intuitive. I finished the free cases already, and I was surprised when I looked at the price and saw it was one payment.
I am a second year data science student and it would have been great to have this in my relational database management systems unit. This website makes it feel easy, and most importantly, engaging.
“Students strengthened their SQL skills through interactive challenges on QueryCase.”
Used in a weekend lab at a community college in the United States, preparing students for the CompTIA Data+ certification. The cohort spent four hours working through cases together, with their licences sponsored.
Course instructor, CompTIA Data+ cohort 2026