Threads Excluding User
A easy SQL mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- SQL
- Difficulty
- easy
- Seniority
- L3
Interview Prompt
The trust and safety team needs to audit messaging activity that doesn't involve user 1. A thread is defined as a unique sender_id and reply_to pair. Count how many threads exist where neither the sender_id nor the reply_to is user 1, considering only messages that have a non-null reply_to.
Summary
Every thread they're not part of.
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