# From transactions, return transaction_id, user_id, total_amount, and LAG(total_amount) OVER (PARTITI

Canonical URL: <https://datadriven.io/problems/from-transactions-return-transactionid-userid-totalamo-7c7237d5>

Domain: SQL · Difficulty: medium

## Problem

From transactions, return transaction_id, user_id, total_amount, and LAG(total_amount) OVER (PARTITION BY user_id ORDER BY transaction_date) AS prev_amount. Order by user_id, transaction_date.

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