The Weight of Every Purchase

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

Domain

SQL

Difficulty

medium

Seniority

mid

Problem

The finance analytics group at our marketplace wants to understand how each shopper's lifetime spend accumulates over time, so they can spot the exact purchase where a customer crosses a high-value threshold and flag them for loyalty outreach. For every purchase a customer has made, they want to see the customer, the date that purchase happened, and how much that customer had spent in total up to and including that purchase, with the timeline read in the order the purchases actually occurred. Walk through one customer's history and the picture is a steadily climbing balance; do this for everyone at once.

Summary

Each order carries everything that came before it. Show the load building, customer by customer.

Practice This Problem

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