Return username and the count of transactions per user using LEFT JOIN so users with no transactions
A medium SQL mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- SQL
- Difficulty
- medium
Interview Prompt
Return username and the count of transactions per user using LEFT JOIN so users with no transactions appear with a 0. Use COUNT(transaction_id) AS tx_count. Order by tx_count descending, then username.
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