Returning Buyers

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

Domain

SQL

Difficulty

medium

Seniority

L4

Problem

The retention team needs repeat-buyer signals. Find users who made a second transaction within 1 to 7 days of a previous one, excluding same-day purchases. Return each qualifying user ID once.

Summary

They came back and bought again.

Practice This Problem

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