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

Domain

SQL

Difficulty

medium

Seniority

L4

Problem

Find users who made at least 1 transaction in both the first half (Jan through Jun) and second half (Jul through Dec) of 2025. Return the user ID.

Summary

First half buyer. Second half buyer. Same person.

Practice This Problem

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