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SQL Average Sales Per Customer

EasySQL · PostgreSQL00:00
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Your question is SQL Average Sales Per Customer. Start with the requirements and the one table on the right.

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Problem

Aimpoint Digital analysts need a customer-level sales summary for a client reporting workflow. Write a PostgreSQL query that calculates the average sale amount for every identified customer.

Requirements

  1. Group sales by customer_id and calculate the average non-null sale_amount.
  2. Exclude sales records that do not have an identified customer, then order customers by average sale amount from highest to lowest.

Schema

sales
ColumnTypeDescription
sale_idPKINTUnique sales transaction identifier
customer_idINTCustomer identifier associated with the sale
sale_amountDECIMAL(10,2)Monetary value of the sale
sale_dateDATEDate on which the sale occurred
Tablessales
Your solutionPostgreSQL
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