Max-Selling Products Across Tables | Dataford Interview Questions

Find the max-selling products from three tables, each containing different products.

Asked in the SQL live coding stage. Write a SQL query that combines the three tables and identifies the product or products with the highest total units sold.

Output

Return one row per product tied for the maximum.
Include product_name and total_units_sold.
Sort results by product_name in ascending order.

Schema

product_sales_a

Column	Type	Description
sale_idPK	INT	Unique identifier for the sales record
product_name	VARCHAR(100)	Name of the product sold
units_sold	INT	Number of units sold in the record

product_sales_b

Column	Type	Description
sale_idPK	INT	Unique identifier for the sales record
product_name	VARCHAR(100)	Name of the product sold
units_sold	INT	Number of units sold in the record

product_sales_c

Column	Type	Description
sale_idPK	INT	Unique identifier for the sales record
product_name	VARCHAR(100)	Name of the product sold
units_sold	INT	Number of units sold in the record

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Problem