User 360
A hard SQL mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- SQL
- Difficulty
- hard
- Seniority
- L6
Interview Prompt
The product team wants a one-row-per-user activity summary, including users with zero activity. For every user, count their rows in transactions and their rows in user_sessions, substituting 0 when either side is empty. Return the username, transaction count, and session count.
Summary
One row per user. Everything they did, or didn't do.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Write your sql solution with real code execution
- Get instant feedback and a hire/no-hire decision