Denormalizing a Table | Dataford Interview Questions

Tell me how you would denormalize a table.

For this exercise, use the normalized tables provided to produce a flattened reporting result. Preserve every order-line record, including records with missing customer or product details.

Output

One row per order line with line_id, order_id, order_date, customer_name, region, sku, product_name, product_family, quantity, unit_price, and line_total
Include all order lines, retain missing descriptive values as NULL, and calculate line_total as quantity multiplied by unit price
Order by order_date, then order_id, then line_id

Schema

customers

Column	Type	Description
customer_idPK	INT	Unique customer identifier
customer_name	VARCHAR(100)	Customer or account name
region	VARCHAR(50)	Customer sales region

products

Column	Type	Description
product_idPK	INT	Unique product identifier
sku	VARCHAR(40)	Stock keeping unit
product_name	VARCHAR(120)	Product name
product_family	VARCHAR(80)	Product family or category

order_lines

Column	Type	Description
line_idPK	INT	Unique order-line identifier
order_id	INT	Order identifier
order_date	DATE	Date the order was placed
customer_id	INT	Referenced customer identifier
product_id	INT	Referenced product identifier
quantity	INT	Units ordered
unit_price	NUMERIC(10,2)	Price per unit

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