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Top Spenders Per Region
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Top Spenders Per Region

MediumSQL · PostgreSQL

Problem

Given a massive table of user transactions, write a query to find the top 3 highest-spending users in each region over the last 30 days.

Use the users and transactions tables. The 30-day window is relative to CURRENT_DATE; exclude users without a region and transactions outside the window.

Output

  1. One row per qualifying user, with region, user_id, user_name, total_spent, and spending_rank.
  2. Include no more than three users per region, ordered by total spending descending, with user_id as the tie-breaker.
  3. Sort the final results by region, then spending_rank.

Schema

users
ColumnTypeDescription
user_idPKINTUnique user identifier
user_nameVARCHAR(100)User display name
regionVARCHAR(50)User's geographic region
transactions
ColumnTypeDescription
transaction_idPKINTUnique transaction identifier
user_idINTUser associated with the transaction
transaction_dateDATEDate on which the transaction occurred
amountNUMERIC(12,2)Transaction amount
Tablesuserstransactions
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