About this app

THE CASE IS OPEN. THE DATABASE IS WAITING. Someone is lying. The records know who. Deadlock Holmes is a noir detective game where you learn SQL by solving murder mysteries. No dialogue trees. No multiple-choice quizzes. No tapping until the answer appears. You write the SQL. The database gives you the evidence. HOW IT WORKS 🕵️ READ THE CASE Get a hardboiled case brief, then study the evidence. ⌨️ WRITE REAL SQL Query phone logs, alibis, ledgers, key-card records, and more using real SQLite. 🔎 FOLLOW THE CLUES Use SELECT, WHERE, JOIN, GROUP BY, subqueries, and other SQL techniques to narrow the suspect pool. 📋 CHECK YOUR RESULTS Your queries actually execute. Make a mistake and SQLite gives you a real error. 🧷 BUILD YOUR CASE Pin useful query results to your Notes. Browse the Schema to understand the tables and columns. ⚖️ NAME YOUR SUSPECT When the evidence is strong enough, make the accusation. Get it wrong and you lose XP. WHY DEADLOCK HOLMES? 🧠 LEARN SQL BY USING IT Forget memorizing syntax for a quiz. Write queries to answer questions that matter. 🗃️ REAL DATABASES, REAL QUERIES This is not a fake SQL simulator. Your investigations run against an embedded SQLite database. ⌨️ BUILT FOR SQL ON MOBILE A custom SQL keyboard gives you keywords, table and column suggestions, JOIN templates, and an in-app SQL guide. 🧩 CASES THAT MAKE YOU THINK Suspects are designed around different clues. You cannot simply eyeball the evidence and guess. 📈 START SIMPLE, GET SHARPER Begin with single-table SELECT and WHERE queries. Work toward JOINs, GROUP BY, and subqueries as cases become more demanding. 💡 HINTS WHEN YOU NEED THEM Progressive hints can point you in the right direction without simply handing over the answer. 🏆 BUILD YOUR DETECTIVE RECORD Save your progress, unlock cases in order, earn XP, climb the detective ranks, and keep your case tally. 🕯️ FULL NOIR ATMOSPHERE Cork pinboards. Red string. Torn case files. Wax seals. Rubber stamps. The whole office looks like trouble. 📴 PLAY OFFLINE No account required. Your investigations can run without an internet connection. WHO IS IT FOR? 🎓 SQL students who want more practice than tutorials provide. 💼 Career switchers learning SQL for their next role. 📊 Analysts building confidence with real queries. 💻 Junior developers preparing for interviews or their first database-heavy role. 🧩 Puzzle fans who want more than trivia and multiple-choice questions. If you have ever learned SQL by staring at examples and thinking, "I understand this," only to freeze when asked to write the query yourself, this is your kind of case. THE QUESTION IS SIMPLE. Who did it? Your SQL query decides. Open the case. Query the evidence. Find the truth.