Second Purchase
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
- L5
Interview Prompt
The onboarding team wants to study second-purchase behavior. For each user with more than one transaction, order their transactions by transaction_date and isolate the second one. Return the user_id, total_amount, and transaction_date of that second purchase.
Summary
The first buy is curiosity. The second is commitment.
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