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SQL for Store Analytics
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SQL for Store Analytics

MediumSQL · PostgreSQL

Problem

Write a SQL query to analyze store performance by location, including total sales, average transaction value, and month-over-month growth.

Use the provided store and transaction data. Include completed transactions only, preserve stores without completed sales, and treat missing monthly sales as zero.

Output

  1. One row per store and calendar month in the overall completed-transaction date range.
  2. Columns: location, month_start, total_sales, average_transaction_value, and month_over_month_growth_pct.
  3. Order by location, then month_start. Growth is NULL when there is no prior month or the prior month has zero sales.

Schema

stores
ColumnTypeDescription
store_idPKINTUnique store identifier
locationVARCHAR(100)Store location
transactions
ColumnTypeDescription
transaction_idPKINTUnique transaction identifier
store_idINTStore where the transaction occurred
transaction_dateDATETransaction date
amountDECIMAL(12,2)Transaction sales amount
statusVARCHAR(20)Transaction processing status
Tablesstorestransactions
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