SQL Protocol: The SQL Game That Teaches Real Queries

2 min read Original article ↗

SQL Protocol is a free, browser-based SQL game. You play a covert operative writing real queries against live databases across a story-driven campaign. No multiple choice. No flashcards. Every mission runs the SQL you type.

What you get

  • 16 story chapters that walk you from SELECT and WHERE through JOINs, GROUP BY, window functions, CTEs, and schema design, ending in a final mission that combines every concept you've learned.
  • Interview Mode (Proving Ground): three floors of timed SQL drills modeled on real technical interviews, from beginner to advanced.
  • Arena (1v1 PvP): competitive SQL matches against other players on the same problem. Fastest correct query wins.
  • XP, levels, and leaderboards that track your progress across the campaign, Proving Ground, and Arena.
  • Free to play. Sign in with Google to save progress. Desktop only, because the typing experience is core to the game.

21 playable chapters total: 16 story, 4 interview-drill floors, and the Arena.

Story campaign: SQL concepts covered

  1. SIGNAL: INTRO - FIRST TRANSMISSION
  2. ARCHIVE: CHAPTER 1 - SELECT, FROM
  3. CIPHER: CHAPTER 2 - WHERE, AND, OR
  4. SAFEHOUSE: CHAPTER 3 - ORDER BY, LIMIT
  5. EXCHANGE: CHAPTER 4 - COUNT, SUM, GROUP BY
  6. FORGE: CHAPTER 5 - INSERT, UPDATE, DELETE
  7. GRID: CHAPTER 6 - LIKE, BETWEEN, WILDCARDS
  8. NETWORK: CHAPTER 7 - JOIN, INNER, LEFT, RIGHT
  9. LAB: CHAPTER 8 - CASE WHEN, COALESCE
  10. DEEP: CHAPTER 9 - SUBQUERIES, EXISTS
  11. TOWER: CHAPTER 10 - CREATE VIEW, CTE
  12. PORT: CHAPTER 11 - UNION, INTERSECT, EXCEPT
  13. WAR ROOM: CHAPTER 12 - ROW_NUMBER, RANK, WINDOW FUNCTIONS
  14. DIRECTOR: CHAPTER 13 - HAVING, COMPLEX JOINS
  15. VAULT: CHAPTER 14 - CREATE TABLE, KEYS, CONSTRAINTS
  16. BREACH: FINAL MISSION - ALL CONCEPTS

Interview Mode: Proving Ground

Three floors of timed, interview-style SQL drills. Ranked by difficulty so you can build pressure gradually or jump straight to the advanced floor.

  • PROVING GROUND: INTERVIEW MODE - LOBBY
  • FLOOR 1: INTERVIEW MODE - BEGINNER DRILLS
  • FLOOR 2: INTERVIEW MODE - INTERMEDIATE DRILLS
  • FLOOR 3: INTERVIEW MODE - ADVANCED DRILLS

Arena: 1v1 PvP

Queue into a head-to-head match against another player on the same SQL problem. Fastest correct query takes the ranking points. Your MMR moves up the Arena leaderboard.

Who it's for

Candidates preparing for data engineering, data analyst, and backend interviews; self-taught developers who want a structured SQL path; and educators looking for a free, game-based teaching tool.

Access

Sign in with Google at sqlprotocol.com. Desktop only, because the typing experience is core to the game.

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