The Undone
A medium SQL mock interview question on DataDriven, with an AI interviewer who asks follow-up questions and a hire or no-hire decision at the end.
- Domain
- SQL
- Difficulty
- medium
- Seniority
- L4
Interview Prompt
A reliability reviewer is going through the `migrations` table database by database. For each database, report its total migrations, how many applied and how many were rolled back, keeping only the databases with at least one rollback for every two applied migrations.
Summary
Some migrations don't stick. Find the databases where they keep coming undone.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Write and run your SQL against a real database
- Answer the interviewer's follow-up questions, then get a hire or no-hire decision