Two-Way Street
A medium SQL mock interview question on DataDriven, with an AI interviewer who asks follow-up questions and a hire or no-hire decision at the end.
- Domain
- SQL
- Difficulty
- medium
- Seniority
- L4
Interview Prompt
In chat_msgs a reply records who wrote it in sender_id and who it answers in reply_to, and the community team treats a reply between two users as one conversation whichever of them sent it. Report how many unique two-person conversations there are and how many different users wrote at least one reply.
Summary
A conversation reads the same from either side.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Write and run your SQL against a real database
- Answer the interviewer's follow-up questions, then get a hire or no-hire decision