The Vanishing Rows
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
A downstream dashboard is reporting fewer content views than expected. The content_views table has 100 records, but some views were logged without a user association. Write a query that pairs content_views to users on user_id and returns each view's ID, user ID, and username. Then reason about why the result has fewer than 100 rows.
Summary
Some records disappear when the tables meet. Figure out why.
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