Deduplicated Sales Volume by Category

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

Domain

SQL

Difficulty

medium

Seniority

senior

Problem

The transactions table contains duplicate records. First deduplicate by keeping only the first occurrence of each transaction (the one with the lowest transaction_id when multiple rows share the same user_id, product_id, total_amount, and transaction_date). Then combine with the products table and compute the total sales amount per product category, only counting transactions where total_amount is positive.

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