From users, return COUNT(*) AS total, COUNT(DISTINCT age_bucket) AS distinct_buckets, and COUNT(age_

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, COUNT(DISTINCT age_bucket) AS distinct_buckets, and COUNT(age_bucket) AS non_null_buckets on one row. (DISTINCT ignores NULL.)

How This Interview Works

1. Read the vague prompt (just like a real interview)
2. Ask clarifying questions to the AI interviewer
3. Write your sql solution with real code execution
4. Get instant feedback and a hire/no-hire decision