Adopters Before Migration

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

Domain

SQL

Difficulty

hard

Seniority

senior

Problem

The product team is measuring organic adoption of the new editor versus the classic editor. In the page views data, visits to the new editor appear under the URL 'new_editor' and visits to the classic editor under 'classic_editor'. Identify users who visited the new editor but had never visited the classic editor before their first new editor visit. Return their user IDs.

Practice This Problem

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