Top Shippers by Volume | Dataford Interview Questions

Convoy's Business Intelligence team needs a quarterly view of shipper volume. Write a PostgreSQL query that returns the top three shippers by completed freight weight during the previous calendar quarter. For the sample data, assume the query runs on August 29, 2026, making April 1 through June 30, 2026 the previous quarter.

Requirements

Join shippers to loads using shipper_id.
Include only completed loads whose pickup_date falls in the previous calendar quarter.
Sum weight_lbs for each shipper, return the top three, and break ties by shipper_id ascending.

Schema

shippers

Column	Type	Description
shipper_idPK	INTEGER	Unique shipper identifier
shipper_name	VARCHAR(100)	Shipper company name

loads

Column	Type	Description
load_idPK	INTEGER	Unique load identifier
shipper_id	INTEGER	References shippers.shipper_id
pickup_date	DATE	Scheduled pickup date
status	VARCHAR(20)	Operational load status
weight_lbs	NUMERIC(12,2)	Freight weight in pounds

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