Flag Sellers With High Return Rates | Dataford Interview Questions

You are given order, return, and seller data. Write a PostgreSQL query that finds sellers with unusually high return rates over the last quarter, where return rate is the number of returned orders divided by total completed orders in that quarter. Return each seller’s ID, seller name, total orders, returned orders, and return rate, and only include sellers whose return rate is above 20%.

Schema

sellers

Column	Type	Description
seller_idPK	INT	Primary key for each seller
seller_name	VARCHAR(255)	Seller display name

orders

Column	Type	Description
order_idPK	INT	Primary key for each order
seller_id	INT	Seller who fulfilled the order
order_date	DATE	Order completion date
order_status	VARCHAR(50)	Order status such as completed or canceled

returns

Column	Type	Description
return_idPK	INT	Primary key for each return
order_id	INT	Order that was returned
return_date	DATE	Date the return was created

Your question is Flag Sellers With High Return Rates. Start with the requirements and the three tables in the Question tab.

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