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

mid

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.

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