Top 3 Records Per Region | Dataford Interview Questions

Your question is Top 3 Records Per Region. Start with the requirements and the two tables on the right.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

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