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

Domain

SQL

Difficulty

medium

Seniority

L4

Problem

For each user in 2025, compute the longest session on a mobile device versus the longest session on a desktop device.

Summary

Mobile versus desktop. Who stays longer?

Practice This Problem

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