The Undone

A hard SQL interview practice problem on DataDriven. Write and execute real sql code with instant grading.

Domain

SQL

Difficulty

hard

Seniority

L4

Problem

A reliability review is auditing the databases where migrations have been rolled back. For each of those databases, report its total migration count and how many of those migrations were rolled back, most rollbacks first.

Summary

Some migrations don't stick. Find the databases where they keep coming undone.

Practice This Problem

Solve this SQL problem with real code execution. DataDriven runs your SQL queries against a real database and grades it automatically.