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SQL: Revenue Per Customer and Change

MediumSQL · PostgreSQL00:00
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Your question is SQL: Revenue Per Customer and Change. Start with the requirements and the one table on the right.

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Problem

Given table column names, write SQL to calculate the revenue per customer for July, and then calculate the change from June to July.

Asked in the Round 1 Video Interview stage.

Output

  1. One row per customer with July revenue and the June to July change.
  2. Include the customer identifier, July revenue, June revenue, and revenue change.
  3. Return only customers with July activity, ordered by customer identifier.

Schema

orders
ColumnTypeDescription
order_idPKINTUnique order identifier
customer_idINTCustomer placing the order
order_dateDATEDate the order was placed
revenueDECIMAL(10,2)Revenue from the order
Tablesorders
Your solutionPostgreSQL
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