From users, return COUNT(*) AS total_users and COUNT(age_bucket) AS with_age on one row; then subtra
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
From users, return COUNT(*) AS total_users and COUNT(age_bucket) AS with_age on one row; then subtract to derive missing_age as total_users - with_age, also on the row.
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