Data Visualization Techniques | Dataford Interview Questions

What techniques do you use for data visualization?

For this SQL exercise, prepare a visualization-ready summary from the available customer and order data. Include only completed orders and preserve NULL values where the source data produces them.

Output

One row per region and calendar month represented by completed orders.
Columns: region, month, completed_orders, revenue, and average_order_value.
Sort by month ascending, then region ascending, with NULL regions first.

Schema

customers

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

orders

Column	Type	Description
order_idPK	INT	Unique order identifier
customer_id	INT	Customer associated with the order
order_date	DATE	Date the order was placed
status	VARCHAR(20)	Order processing status
amount	NUMERIC(10,2)	Order amount

Your question is Data Visualization Techniques. Start with the requirements and the two tables in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem