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SQL Top 5 Customers by Revenue

EasySQL · PostgreSQL00:00
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Your question is SQL Top 5 Customers by Revenue. Start with the requirements and the two tables on the right.

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Problem

Confluent's customer analytics team needs a ranked view of its highest-revenue customers. Assuming the reporting date is January 1, 2026, write a PostgreSQL query to find the top five customers by completed-order revenue during the previous calendar year, January 1 through December 31, 2025.

Requirements

  1. Include only orders with status = 'completed' and an order_date in the 2025 calendar year.
  2. Join qualifying orders to customers and aggregate revenue by customer.
  3. Return the top five customers, ordered by revenue descending, with customer_id as a deterministic tie-breaker.

Schema

customers
ColumnTypeDescription
customer_idPKINTEGERUnique customer identifier
customer_nameVARCHAR(100)Customer or organization name
segmentVARCHAR(30)Customer segment
orders
ColumnTypeDescription
order_idPKINTEGERUnique order identifier
customer_idINTEGERCustomer associated with the order
order_dateDATEDate the order was placed
statusVARCHAR(20)Order processing status
total_amountNUMERIC(12,2)Order revenue amount
Tablescustomersorders
Your solutionPostgreSQL
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