The Address That Changed
A hard SQL mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- SQL
- Difficulty
- hard
- Seniority
- L5
Interview Prompt
We keep the full address history for every customer, one row per address they've ever lived at, tagged with that address's country. For each customer who has moved at least once, return a row for every address on file showing their customer_id, first_name, that address's country, and their total number of moves.
Summary
Addresses change. History must not be erased.
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