Top-N Ranking with Window Functions | Dataford Interview Questions

Write a SQL query using window functions to rank customers within each segment by predicted value and return the top 3 per segment.

Use the provided customer and segment data. Exclude customers without a segment or predicted value, and break equal predicted values by ascending customer ID.

Output

One row per selected customer, with customer_id, customer_name, segment_name, predicted_value, and segment_rank
Include up to three customers per segment
Order by segment_name, then segment_rank, then customer_id

Schema

customers

Column	Type	Description
customer_idPK	INT	Unique customer identifier
customer_name	VARCHAR(100)	Customer display name
segment_id	INT	Customer segment identifier
predicted_value	NUMERIC(12,2)	Predicted customer value

customer_segments

Column	Type	Description
segment_idPK	INT	Unique segment identifier
segment_name	VARCHAR(100)	Segment display name

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Problem