Multi-OS Users

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

Domain

SQL

Difficulty

easy

Seniority

L4

Problem

A downstream consumer flagged missing cross-platform users. Find users who have logged in from devices running different operating systems across sessions. A user qualifies if they have more than one unique OS name. Return all session records for qualifying users, including user ID, OS name, device type, and session start.

Summary

iOS today, Android tomorrow.

Practice This Problem

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