Top 3 Records Per Region | Dataford Interview Questions

Lynker Technologies wants to identify the highest-value sales records within each operating region. Write a PostgreSQL query that ranks records independently within each known region and returns the top three.

Requirements

Join sales records to regions to display the region name.
Treat a NULL sales amount as zero when ranking, while preserving the original sales value in the output.
Return no more than three records per region, ordered by sales descending and sale_id ascending as the tie-breaker.
Exclude sales records whose region is not present in regions.

Schema

regions

Column	Type	Description
region_idPK	INT	Unique region identifier
region_name	VARCHAR(50)	Display name of the operating region

sales_records

Column	Type	Description
sale_idPK	INT	Unique sales record identifier
region_id	INT	Region associated with the sales record
record_label	VARCHAR(100)	Short description of the sales record
sales_amount	NUMERIC(12,2)	Sales amount used for ranking

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